Communication method, communication apparatus, and system

Abstract

The application discloses a communication method, a communication device and a system. The method comprises the following steps: acquiring first indication information and / or second information, the second information comprising second indication information or third indication information, the first indication information being used for indicating first time advance information used by a terminal device for performing first uplink transmission when the terminal device accesses a first cell based on a random access-free mode, the second indication information being used for indicating second time advance information used by the terminal device for accessing the first cell based on a random access mode, the terminal device accessing the first cell based on the random access mode being triggered by failure of the terminal device accessing the first cell based on the random access-free mode, and the third indication information being used for indicating third time advance information used by the terminal device for performing second uplink transmission after the terminal device successfully accesses the first cell based on the random access-free mode; and performing mobility parameter optimization analysis based on the information. The method can reduce mobility abnormality problems.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to communication methods, communication devices, and systems. Background Technology

[0002] Layer 1 / L2 triggered mobility (LTM) can reduce mobility latency. LTM enables serving cell changes based on L1 / L2 signaling. For example, a network device receives an L1 measurement report from a terminal device, and then the network device can instruct the terminal device to change the serving cell (or switch from the source cell to the target cell) via a handover command; the terminal device can then perform random access without a random signal after receiving the handover command.

[0003] Currently, in scenarios involving terminal device handover, mobility anomalies such as failed random access or excessively rapid failure of timing advance (TA) exist. Reducing these mobility anomalies is a pressing issue that needs to be addressed. Summary of the Invention

[0004] This application discloses a communication method, communication device, and system that can perform mobility parameter optimization analysis based on time lead information, thereby reducing mobility anomaly problems.

[0005] The following sections describe this application from different perspectives. It should be understood that the implementation methods and beneficial effects of the different aspects described below can be used for mutual reference.

[0006] Firstly, this application provides a communication method, which can be executed by a first communication device. The first communication device can be a network device or a chip, chip system, module, or control unit of the network device, such as a server on the network side or components within the server (e.g., circuits, chips, or chip systems). This application does not specifically limit the scope of the method. It should be noted that, in this application, the term "network device" can refer to either the network device itself or the chip, functional module, or integrated circuit that performs the method provided in this application. This application does not specifically limit the scope of the method.

[0007] For example, the first communication device may be a distributed unit (DU).

[0008] Taking the method as an example of being executed by a first communication device, the method may include: the first communication device receiving first indication information, the first indication information being used to indicate first timing advance information, the first timing advance information being the timing advance information used by the terminal device to perform the first uplink transmission when accessing the first cell in a non-random access manner; and performing mobility parameter optimization analysis based on the first indication information.

[0009] In this embodiment of the application, the first communication device can obtain the time advance information (i.e., the first time advance information) used for the first uplink transmission when accessing the first cell in a non-random access manner. Then, the first communication device can perform mobility parameter optimization analysis based on the first time advance information, such as optimizing mobility parameters such as the acquisition time of the time advance or the validity period of the time advance, thereby optimizing the time advance management mechanism and improving the mobility robustness optimization mechanism.

[0010] Optionally, the first communication device can be a DU to which the first cell belongs. Or, the first cell is a cell managed by the first communication device.

[0011] For example, the first cell can be the source cell of the terminal device (referred to as the second cell for convenience) indicating the target cell to which the terminal device will hand over. If the terminal device receives a handover command sent by the second cell, the handover command instructs the terminal device to hand over from the second cell to the first cell. This application does not limit the names of the first cell and the first communication device. For example, the first cell can also be called the target cell. If the first communication device is the DU to which the first cell belongs, for convenience, the DU can also be called the target DU of the terminal device (abbreviated as target DU).

[0012] For example, the DU to which the second cell belongs can be the fourth communication device (or source DU). The fourth communication device (such as the source DU) can send the first instruction information to the first communication device (such as the target DU). Correspondingly, the first communication device receives the first instruction information sent by the fourth communication device.

[0013] In this application, the time advance can also be referred to as TA or TA value (timing advance value), and this application does not limit it.

[0014] In conjunction with the first aspect, in one possible implementation, the aforementioned mobility parameter optimization analysis based on the first indication information includes: performing mobility parameter optimization analysis based on the first indication information and the second indication information; or, performing mobility parameter optimization analysis based on the first indication information and the third indication information; wherein, the second indication information is used to instruct the terminal device to use second timing advance information for accessing the first cell based on random access (RA), the access to the first cell based on random access being triggered by the failure of access to the first cell based on RA-less access; the third indication information is used to instruct the terminal device to use third timing advance information for second uplink transmission after successfully accessing the first cell, or to instruct the terminal device to use third timing advance information for second uplink transmission after a timing advance adjustment occurs.

[0015] In this embodiment, if the terminal device fails to access the first cell using the non-random access method and instead accesses the first cell using the random access method, the first communication device can perform mobility parameter optimization analysis based on first indication information and second indication information. The second indication information is used to indicate the second timing advance information used by the terminal device to access the first cell using the random access method. In this method, the first communication device performs mobility parameter optimization analysis based on the timing advance information of the terminal device's two accesses to the first cell (i.e., the first timing advance information and the second timing advance information), so that subsequent network-side communication devices can optimize the timing advance information used by the terminal device for non-random access based on the results of the optimization analysis, thereby reducing the occurrence of non-random access handover failures.

[0016] For example, the first communication device is the target DU of the terminal device. Since the target DU knows the second time advance information used by the terminal device to access the first cell based on random access, the target DU can obtain the time advance information (i.e., the first time advance information and the second time advance information) of the terminal device when accessing the first cell twice by receiving the first instruction information to perform mobility parameter optimization analysis.

[0017] In this embodiment, if a terminal device successfully accesses the first cell without random access, and performs a first uplink transmission based on first timing advance information, and then performs a second uplink transmission using third timing advance information after successfully accessing the first cell, the first communication device can perform mobility parameter optimization analysis based on first indication information and third indication information, wherein the third indication information is used to indicate the third timing advance information. In this method, the first communication device performs mobility parameter optimization analysis based on the timing advance information (i.e., the first timing advance information and the third timing advance information) used for the two uplink transmissions after the terminal device successfully accesses the first cell without random access. This allows subsequent network-side communication devices (such as a third communication device or other communication devices) to optimize the timing advance acquisition process and validity management process of the terminal device using the results of the optimization analysis, thereby reducing the likelihood of the terminal device quickly adjusting the timing advance after achieving random access.

[0018] For example, the first communication device is the target DU of the terminal device. Since the target DU knows that the terminal device uses the third time advance information after successfully accessing the first cell, the target DU can obtain the time advance information (i.e. the first time advance information and the third time advance information) used by the terminal device to perform two uplink transmissions after successfully accessing the first cell in a way that avoids random access by receiving the above-mentioned first indication information, so as to perform mobility parameter optimization analysis.

[0019] In conjunction with the first aspect, in one possible implementation, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to indicate a first timing advance to the terminal device, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0020] Optionally, the first indication information is used to indicate that the second cell sends a time advance to the terminal device; or, the first indication information is used to indicate that no time advance is sent to the terminal device; or, the first indication information is used to indicate that the second cell indicates a first time advance to the terminal device; or, the first indication information is used to indicate that the second cell sends a time advance to the terminal device, and the first indication information is also used to indicate a first time advance.

[0021] For example, if the first indication information is used to indicate that the first time advance has not been sent to the terminal device, then the terminal device does not use the time advance provided by the network side to perform non-random access. In this case, the first communication device recognizes that the failure of the terminal device to access the first cell in a non-random access manner is not due to the first time advance, but may be due to the time advance calculated by the terminal device itself or other parameters.

[0022] In conjunction with the first aspect, in one possible implementation, the first indication information may be included in one or more of the following: CU-DU CELL SWITCH NOTIFICATION message, DU-CU CELLSWITCH NOTIFICATION message, UL RRC MESSAGE TRANSFER message, and DL RRC MESSAGE TRANSFER message. The first indication information is used to indicate whether the Layer 1 / L2 triggered mobility (LTM) handover command sent by the second cell to the terminal device includes a timing advance, and / or whether the LTM handover command includes a first timing advance, and whether the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0023] Optionally, the first indication information is used to indicate that the LTM handover command sent by the second cell to the terminal device includes a first timing advance; or, the first indication information is used to indicate that the LTM handover command sent by the second cell to the terminal device does not include a first timing advance; or, the first indication information is used to indicate the value of the first timing advance included in the LTM handover command; or, the first indication information is used to indicate that the LTM handover command sent by the second cell to the terminal device includes a first timing advance, and the first indication information is also used to indicate the value of the first timing advance included in the LTM handover command.

[0024] For example, the LTM handover command can be sent to the terminal device through the Media Access Control (MAC-CE) element. In this application, the handover command and the LTM handover command can be described interchangeably.

[0025] In conjunction with the first aspect, in one possible implementation, second information is sent, which includes second or third instruction information. For example, the second information may also include an identifier for identifying the terminal device.

[0026] In conjunction with the first aspect, in one possible implementation, the method further includes: sending first information, wherein the first information includes at least one of the following: the failure to access the first cell without random access is caused by an invalid timing advance, a first timing advance, a second timing advance, or a first difference, wherein the first difference is the difference between the first timing advance and the second timing advance, the first timing advance is the timing advance used by the terminal device to perform a first uplink transmission when accessing the first cell without random access, and the second timing advance is the timing advance used by the terminal device to access the first cell based on random access.

[0027] In this embodiment of the application, the first communication device can send the first information to other communication devices so that the other communication devices can optimize the timing advance acquisition process and validity period management process of the terminal device for non-random access through the first information.

[0028] Secondly, this application provides a communication method that can be executed by a second communication device. This second communication device can be a network device or a chip, chip system, module, or control unit of the network device, such as a server on the network side or components within the server (e.g., circuits, chips, or chip systems). This application does not specifically limit the scope of the method. It should be noted that, in this application, the term "network device" can refer to either the network device itself or the chip, functional module, or integrated circuit that performs the method provided in this application. This application does not specifically limit the scope of the method.

[0029] For example, the second communication device may be a centralized unit (CU).

[0030] Taking the method executed by a second communication device as an example, the method may include: the second communication device receiving first indication information, the first indication information being used to indicate first timing advance information, the first timing advance information being timing advance information used by the terminal device to perform a first uplink transmission when accessing the first cell using a non-random access method; receiving second information, the second information including second indication information or third indication information, wherein the second indication information is used to indicate second timing advance information used by the terminal device to access the first cell using a random access method, the access to the first cell using a random access method being triggered by a failure to access the first cell using a non-random access method, and the third indication information is used to indicate third timing advance information used by the terminal device to perform a second uplink transmission after successfully accessing the first cell using a non-random access method, or to indicate third timing advance information used by the terminal device to perform a second uplink transmission after a timing advance adjustment occurs; performing mobility parameter optimization analysis based on the first indication information and the second information, or sending the first indication information and / or the second information.

[0031] In this embodiment, if the terminal device fails to access the first cell using the non-random access method and instead accesses the first cell using the random access method, the second communication device can perform mobility parameter optimization analysis based on the first indication information and the second indication information. The second indication information is used to indicate the second timing advance information used by the terminal device to access the first cell using the random access method. In this method, the second communication device performs mobility parameter optimization analysis based on the timing advance information of the terminal device's two accesses to the first cell (i.e., the first timing advance information and the second timing advance information). This allows subsequent network-side communication devices to optimize the timing advance information used by the terminal device for non-random access based on the optimization analysis results, thus improving the mobility robustness optimization mechanism and reducing the occurrence of non-random access handover failures.

[0032] If the terminal device successfully accesses the first cell without random access, and performs a first uplink transmission based on the first timing advance information, and then performs a second uplink transmission using the third timing advance information after successfully accessing the first cell, the second communication device can perform mobility parameter optimization analysis based on the first and third indication information, where the third indication information is used to indicate the third timing advance information. In this method, the second communication device performs mobility parameter optimization analysis based on the timing advance information used for the two uplink transmissions after the terminal device successfully accesses the first cell without random access (i.e., the first and third timing advance information). This allows subsequent network-side communication devices to optimize the timing advance information used by the terminal device for access-free access based on the optimization analysis results, thus improving the mobility robustness optimization mechanism and reducing the need for the terminal device to adjust the timing advance information after access-free access.

[0033] In conjunction with the second aspect, in one possible implementation, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to indicate a first timing advance to the terminal device, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0034] In conjunction with the second aspect, in one possible implementation, the first indication information can be received through one or more of the following: a DU-CU cell switch notification message, an uplink RRC message transfer message (UL RRC message TRANSFER), or a DU-CU access and mobility indication message. The first indication information can also be sent through one or more of the following: a CU-DU cell switch notification message, a DL RRC message transfer message (DL RRC message TRANSFER), or an access and mobility indication message. Alternatively, the received first indication information may include one or more of the following: a DU-CU cell switch notification message, an uplink RRC message transfer message, or an access and mobility indication message. The sent first indication information may also include one or more of the following: a DU-CU cell switch notification message, an uplink RRC message transfer message, or an access and mobility indication message. The first indication information is used to indicate whether the mobility handover command triggered by Layer 1 / Layer 2 sent by the second cell to the terminal device includes a time advance, and / or whether the mobility handover command triggered by Layer 1 / Layer 2 includes a first time advance, and the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0035] In conjunction with the second aspect, in one possible implementation, the second information includes one or more of the following: a handover success message (AccessSuccess message), an uplink RRC transfer message, or an Access and Mobility Indication (DU-CU) message. For example, the second information also includes an identifier for identifying the terminal device.

[0036] In conjunction with the second aspect, in one possible implementation, the method further includes: sending first information, wherein the first information includes at least one of the following: the failure to access the first cell without random access is caused by an invalid timing advance, a first timing advance, a second timing advance, or a first difference, wherein the first difference is the difference between the first timing advance and the second timing advance, the first timing advance is the timing advance used by the terminal device to perform a first uplink transmission when accessing the first cell without random access, and the second timing advance is the timing advance used by the terminal device to access the first cell based on random access.

[0037] Thirdly, this application provides a communication method that can be executed by a third communication device. This third communication device can be a network device or a chip, chip system, module, or control unit of the network device, such as a server on the network side or components within the server (e.g., circuits, chips, or chip systems). This application does not specifically limit the scope of the method. It should be noted that, in this application, the term "network device" can refer to either the network device itself or the chip, functional module, or integrated circuit that implements the method provided in this application. This application does not specifically limit the scope of the method.

[0038] For example, the third communication device may be a DU.

[0039] Taking the method executed by a third communication device as an example, the method may include: the third communication device receiving second information, the second information including second indication information or third indication information, wherein the second indication information is used to instruct the terminal device to use second timing advance information for accessing the first cell based on random access, the access to the first cell based on random access is triggered by the failure of access to the first cell without random access, the third indication information is used to instruct the terminal device to execute the third timing advance information for second uplink transmission after successfully accessing the first cell without random access, or to instruct the terminal device to execute the third timing advance information for second uplink transmission after a timing advance adjustment occurs; based on the second information, performing mobility parameter optimization analysis.

[0040] In conjunction with the third aspect, in one possible implementation, second information is received, which includes second indication information or third indication information. For example, the second information may include one or more of a downlink RRC message transfer message or an access and mobility indication message. For example, the second information may also include an identifier for identifying the terminal device.

[0041] In conjunction with the third aspect, in one possible implementation, the method further includes: receiving first instruction information.

[0042] For example, the first indication information is included in the Access and Mobility Indication message.

[0043] In this embodiment of the application, the third communication device performs mobility parameter optimization analysis based on the second information, thereby improving the mobility robustness optimization mechanism. For example, it optimizes mobility parameters such as the acquisition time of the time lead or the validity period of the time lead, optimizes the time lead management mechanism, and improves the mobility robustness optimization mechanism.

[0044] For example, the second cell can be the source cell of the terminal device (referred to as the second cell for convenience) indicating the target cell for the terminal device to hand over. For instance, if the terminal device receives a handover command sent by the second cell, the handover command is used to instruct the terminal device to hand over from the second cell to the first cell. The third communication device can be the DU to which the second cell belongs.

[0045] This application does not limit the names of the second cell and the third communication device. For example, the second cell can also be called the source cell. If the third communication device is the DU to which the second cell belongs, for ease of description, the DU can also be called the source DU of the terminal device (abbreviated as source DU).

[0046] For example, the DU to which the first cell belongs can be the fifth communication device (or target DU). Then, the fifth communication device (such as target D) can send the aforementioned second information to the third communication device (such as source DU), and correspondingly, the third communication device receives the second information sent by the fifth communication device.

[0047] In conjunction with the third aspect, in one possible implementation, the third communication device also receives first indication information. For example, the third communication device receives the first indication information via an access and mobility indication message, or receives both the first indication information and the second information simultaneously via an access and mobility indication message.

[0048] In conjunction with the third aspect, in one possible implementation, mobility parameter optimization analysis is performed based on the second information, including: performing mobility parameter optimization analysis based on the first indication information and the second indication information; or, performing mobility parameter optimization analysis based on the first indication information and the third indication information; wherein, the first indication information is used to indicate the first timing advance information, and the first timing advance information is the timing advance information used by the terminal device to perform the first uplink transmission when accessing the first cell in a non-random access manner.

[0049] In this embodiment, if the terminal device fails to access the first cell via non-random access and instead accesses the first cell via random access, the third communication device can perform mobility parameter optimization analysis based on first and second indication information. The second indication information indicates the second timing advance information used by the terminal device to access the first cell via random access. In this method, the third communication device performs mobility parameter optimization analysis based on the timing advance information of the terminal device's two accesses to the first cell (i.e., the first and second timing advance information), so that the timing advance information used by the terminal device for non-random access can be optimized subsequently using the results of the optimization analysis, thereby reducing the occurrence of non-random access handover failures.

[0050] For example, the third communication device is the source DU of the terminal device. Since the source DU knows the first time advance information used by the terminal device to perform the first uplink transmission when it accesses the first cell in a non-random access manner, the target DU can obtain the time advance information (i.e., the first time advance information and the second time advance information) of the terminal device when it accesses the first cell twice by receiving the above-mentioned second indication information in order to perform mobility parameter optimization analysis.

[0051] In this embodiment, if the terminal device successfully accesses the first cell without random access, and performs a first uplink transmission based on the first timing advance information, and then performs a second uplink transmission using the third timing advance information after successfully accessing the first cell, the third communication device can perform mobility parameter optimization analysis based on the first indication information and the third indication information, wherein the third indication information is used to indicate the third timing advance information. In this method, the third communication device performs mobility parameter optimization analysis based on the timing advance information used for the two uplink transmissions after the terminal device successfully accesses the first cell without random access (i.e., the first timing advance information and the third timing advance information), so that the timing advance information used by the terminal device for access-free access can be optimized subsequently using the results of the optimization analysis, thereby reducing the need for the terminal device to adjust the timing advance information after access-free access.

[0052] For example, the third communication device is the source DU of the terminal device. Since the source DU knows the timing advance information used by the terminal device to perform the first uplink transmission when it accesses the first cell in a non-random access manner, the target DU can obtain the timing advance information (i.e., the first timing advance information and the third timing advance information) used by the terminal device to perform two uplink transmissions after successfully accessing the first cell in a non-random access manner by receiving the above-mentioned third indication information, so as to perform mobility parameter optimization analysis.

[0053] In conjunction with the third aspect, in one possible implementation, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to indicate a first timing advance to the terminal device, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0054] In conjunction with the third aspect, in one possible implementation, the second information also includes an identifier for identifying the terminal device.

[0055] Fourthly, this application provides a communication method that can be executed by a fourth communication device. This fourth communication device can be a network device or a chip, chip system, module, or control unit of the network device, such as a server on the network side or components within the server (e.g., circuits, chips, or chip systems). This application does not specifically limit the scope of the method. It should be noted that, in this application, the term "network device" can refer to either the network device itself or the chip, functional module, or integrated circuit that performs the method provided in this application. This application does not specifically limit the scope of the method.

[0056] For example, the fourth communication device can be a DU. For instance, the DU can be the DU to which the source cell of the terminal device belongs; for ease of description, the DU can be referred to as the source DU.

[0057] Taking the method as an example of being executed by a fourth communication device, the method may include: the fourth communication device sending first indication information, the first indication information being used to indicate first timing advance information, the first timing advance information being the timing advance information used by the terminal device to perform the first uplink transmission when accessing the first cell in a non-random access manner, and the first indication information being used for mobility parameter optimization analysis.

[0058] In conjunction with the fourth aspect, in one possible implementation, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to indicate a first timing advance to the terminal device, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0059] In conjunction with the fourth aspect, in one possible implementation, the first indication information is included in the handover notification message, wherein the first indication information is used to indicate whether the layer 1 / layer 2 triggered mobility handover command sent by the second cell to the terminal device includes a timing advance, and / or the layer 1 / layer 2 triggered mobility handover command includes a first timing advance, and the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0060] In conjunction with the fourth aspect, in one possible implementation, the method further includes: receiving first information, the first information being determined based on first instruction information.

[0061] In conjunction with the fourth aspect, in one possible implementation, the first information includes at least one of the following: the failure to access the first cell without random access is caused by an invalid time advance, a first time advance, a second time advance, or a first difference, wherein the first difference is the difference between the first time advance and the second time advance, the first time advance is the time advance used by the terminal device to perform the first uplink transmission when accessing the first cell without random access, and the second time advance is the time advance used by the terminal device to access the first cell based on random access.

[0062] Fifthly, this application provides a communication method that can be executed by a fifth communication device. This fifth communication device can be a network device or a chip, chip system, module, or control unit of the network device, such as a server on the network side or components within the server (e.g., circuits, chips, or chip systems). This application does not specifically limit the scope of the method. It should be noted that, in this application, the term "network device" can refer to either the network device itself or the chip, functional module, or integrated circuit that performs the method provided in this application. This application does not specifically limit the scope of the method.

[0063] For example, the fifth communication device can be a DU. For instance, the DU can be the DU to which the target cell to which the terminal device is accessed belongs; for ease of description, this DU will be referred to as the target DU.

[0064] Taking the method executed by a fifth communication device as an example, the method may include: the fifth communication device sending second information, the second information including second indication information or third indication information, the second information being used for mobility parameter optimization analysis, wherein the second indication information is used to instruct the terminal device to use second timing advance information for accessing the first cell based on random access, the access to the first cell based on random access being triggered by the failure of access to the first cell without random access, the third indication information is used to instruct the terminal device to execute third timing advance information for second uplink transmission after successfully accessing the first cell without random access, or to instruct the terminal device to execute third timing advance information for second uplink transmission after a timing advance adjustment occurs.

[0065] In conjunction with the fifth aspect, in one possible implementation, the second information also includes an identifier for identifying the terminal device.

[0066] Sixthly, this application provides a communication device, which may be a first communication device or a chip / circuit of a first communication device. The communication device is used to perform the methods in the first aspect or any possible implementation thereof. The communication device includes units having the ability to perform the methods in the first aspect or any possible implementation thereof.

[0067] In a seventh aspect, this application provides a communication device, which may be a second communication device or a chip / circuit within a second communication device. The communication device is used to perform the method in the second aspect or any possible implementation thereof. The communication device includes units having the ability to perform the method in the second aspect or any possible implementation thereof.

[0068] Eighthly, this application provides a communication device, which may be a third communication device or a chip / circuit of a third communication device. The communication device is used to execute the methods in the third aspect or any possible implementation thereof. The communication device includes units having the ability to execute the methods in the third aspect or any possible implementation thereof.

[0069] Ninthly, this application provides a communication device, which may be a fourth communication device or a chip / circuit within a fourth communication device. The communication device is used to perform the methods in the fourth aspect or any possible implementation thereof. The communication device includes units having the ability to perform the methods in the fourth aspect or any possible implementation thereof.

[0070] Tenthly, this application provides a communication device, which may be a fifth communication device or a chip / circuit of a fifth communication device. The communication device is used to perform the methods in the fifth aspect or any possible implementation thereof. The communication device includes units having the ability to perform the methods in the fifth aspect or any possible implementation thereof.

[0071] In any of the sixth to tenth aspects, the aforementioned communication apparatus may include a transceiver unit and a processing unit. Further details regarding the transceiver unit and processing unit can be found in the apparatus embodiments shown below. The beneficial effects of the sixth to tenth aspects can be referenced in the relevant descriptions of the first to fifth aspects, and will not be repeated here.

[0072] In one aspect, this application provides a communication device, which includes a processor for executing the method described in any possible implementation of the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, or any of the aspects described above.

[0073] In a twelfth aspect, this application provides a communication device including a processor coupled to a memory storing instructions that, when executed by the processor, cause the communication device to perform the method described in any possible implementation of the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, or any of the aspects described above.

[0074] In one possible implementation, the communication device further includes a memory. Optionally, the processor and memory are integrated (i.e., the memory is built-in memory). Optionally, the memory and processor are independently configured (i.e., the memory is external memory).

[0075] In a thirteenth aspect, this application provides a communication device that may include a processor and an interface circuit connected together. The interface circuit is used for exchanging (or sending / receiving or inputting / outputting) information or data, and the processor is used to execute program instructions that cause the communication device to perform the methods described in any possible implementation of the first, second, third, fourth, or fifth aspect above. The interface circuit may be a communication interface or a transceiver. The transceiver may be a radio frequency module in the communication device, or a combination of a radio frequency module and an antenna, or an input / output interface of a chip or circuit.

[0076] In a fourteenth aspect, this application provides a readable storage medium storing program instructions that, when run on a computer, cause the computer to perform the method described in any possible implementation of the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, or any of the aspects described above.

[0077] In a fifteenth aspect, this application provides a program product containing program instructions that, when executed, cause the method described in any possible implementation of the first aspect, or the second aspect, or the third aspect, or the fourth aspect, or the fifth aspect, or any of these aspects, to be performed.

[0078] In a sixteenth aspect, this application provides an apparatus, which can be implemented as a chip or as a device, including a processor. The processor is used to read and execute a program stored in a memory to perform one or more of the first, second, third, fourth, or fifth aspects described above, or one or more of any possible implementations of any of these aspects, providing an information interaction method. Optionally, the apparatus further includes a memory connected to the processor via a circuit. Further optionally, the apparatus includes a communication interface to which the processor is connected. The communication interface is used to receive information to be processed, the processor obtains the information from the communication interface, processes the information, and outputs the processing result through the communication interface. The communication interface can be an input / output interface.

[0079] In one possible implementation, the processor and memory can be physically independent units, or the memory can be integrated with the processor.

[0080] In a seventeenth aspect, this application provides a communication system comprising a first communication device (such as a target DU) and a fourth communication device (such as a source DU); wherein the first communication device is configured to perform the method described in the first aspect or any possible implementation thereof, and the fourth communication device is configured to perform the method described in the fourth aspect or any possible implementation thereof.

[0081] In an eighteenth aspect, this application provides a communication system comprising a second communication device (e.g., a CU), a fourth communication device (e.g., a source DU), and a fifth communication device (e.g., a target DU); wherein the second communication device is configured to perform the method described in the second aspect or any possible implementation thereof, the fourth communication device is configured to perform the method described in the fourth aspect or any possible implementation thereof, and the fifth communication device is configured to perform the method described in the fifth aspect or any possible implementation thereof.

[0082] In a nineteenth aspect, this application provides a communication system comprising a third communication device (such as a source DU) and a fifth communication device (target DU); wherein the third communication device is used to perform the method described in the third aspect above, or any possible implementation of the third aspect, and the fifth communication device is used to perform the method described in the fifth aspect above, or any possible implementation of the fifth aspect.

[0083] In this application, the first communication device and the fifth communication device may be two separate communication devices (e.g., two separate DUs); or the first communication device and the fifth communication device may be the same communication device (e.g., the same DU), that is, the communication device may be used to execute any possible implementation of the first aspect, or the fifth aspect, or any one of them.

[0084] In this application, the third communication device and the fourth communication device may be two separate communication devices (e.g., two separate DUs); or the third communication device and the fourth communication device may be the same communication device (e.g., the same DU), that is, the communication device may be used to execute any possible implementation of the third aspect, the fourth aspect, or any one of them.

[0085] The technical effects achieved in the above aspects can be referred to each other or to the beneficial effects in the method embodiments shown below, which will not be repeated here. Attached Figure Description

[0086] Figure 1A This is a schematic diagram of the architecture of the communication system used in the embodiments of this application;

[0087] Figure 1B This is a schematic diagram of an O-RAN system architecture provided in this application;

[0088] Figure 1C This is a schematic diagram of another architecture of the O-RAN system provided in this application;

[0089] Figure 1D This is a schematic diagram of the network element function division and protocol layer structure of an O-RAN device provided in this application;

[0090] Figure 1E These are schematic diagrams illustrating the structures of two base stations provided in the embodiments of this application.

[0091] Figure 2A and Figure 2B Two possible scenarios are illustrated in the example;

[0092] Figures 3 to 8 This is a flowchart illustrating some communication methods provided in the embodiments of this application;

[0093] Figure 9 This is a schematic diagram of the structure of the communication device provided in an embodiment of this application;

[0094] Figure 10 This is another structural schematic diagram of the communication device provided in the embodiments of this application;

[0095] Figure 11 This is another structural schematic diagram of the communication device provided in the embodiments of this application. Detailed Implementation

[0096] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0097] In the description of this application, the terms "first," "second," etc., are used only to distinguish different objects and do not limit the quantity or order of execution, nor do they imply that they are necessarily different. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0098] In the description of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. "And / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one item", "one or more of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a and b and c. Here, a, b, and c can be single or multiple.

[0099] In the description of this application, the words "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design that is described as "exemplary," "for example," or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the words "exemplary," "for example," or "for example" is intended to present the relevant concepts in a specific manner.

[0100] It is understood that in the description of this application, "when," "if," and "if" all refer to the device performing a corresponding action under certain objective circumstances, and are not time-limited, nor do they require the device to perform a judgment action when it is implemented, nor do they imply any other limitations. The device performing a corresponding action under certain objective circumstances includes: satisfying the objective circumstances, i.e., being able to perform the corresponding action; or satisfying both the objective circumstances and other circumstances, in order to perform the corresponding action.

[0101] In this application, the use of singular designations for elements is intended to represent "one or more" rather than "one and only one," unless otherwise specified.

[0102] In addition, the terms “system” and “network” are often used interchangeably in this article.

[0103] It is understood that in the various embodiments of this application, expressions such as "A corresponds to B", "A and B correspond", "A corresponds to B" or similar expressions indicate that B is associated with A, and B can be determined based on A. Determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0104] Please see Figure 1A , Figure 1A This is a schematic diagram of the architecture of the communication system used in the embodiments of this application. It should be noted that... Figure 1A This is a schematic diagram of one possible, non-limiting system. For example... Figure 1AAs shown, the communication system 10 includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the communication system 10 may also include an Internet 300. The RAN 100 includes at least one RAN node (e.g., Figure 1A 110a and 110b (collectively referred to as 110) and at least one terminal device (such as Figure 1A RAN 100, denoted as RAN 120a-120j, is collectively referred to as RAN 120. RAN 100 may also include other RAN nodes, such as wireless relay equipment and / or wireless backhaul equipment. Figure 1A (Not shown in the image). Terminal device 120 is connected to RAN node 110 wirelessly. RAN node 110 is connected to core network 200 wirelessly or via wired connection. The core network elements in core network 200 and RAN node 110 in RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and radio access network logical functions, or they can be a single physical device integrating some core network element functions and some RAN node 110 functions. Terminal devices can be interconnected with each other, and RAN nodes 110 can be interconnected with each other via wired or wireless connection. Figure 1A This is just a schematic diagram. The communication system may also include other network devices, such as wireless repeaters and wireless backhaul devices. Each device may also contain different functional units. Figure 1A It is not shown in the middle.

[0105] In this embodiment, any one of the first to fifth communication devices can be... Figure 1A RAN node 110 in the middle.

[0106] In this application, RAN node 110 can also be referred to as a network device.

[0107] RAN 100 can be a cellular system related to the 3rd Generation Partnership Project (3GPP), such as 4G, 5G mobile communication systems, or future-oriented evolution systems. RAN 100 can also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. RAN 100 can also be a communication system that integrates two or more of the above systems.

[0108] RAN node 110, sometimes also referred to as radio access network equipment, access network device, access network apparatus, RAN entity, or access node, constitutes part of the communication system and is used to help terminal equipment achieve wireless access. Multiple RAN nodes 110 in the communication system 10 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal equipment 120 are relative, for example... Figure 1A Network element 120i can be a helicopter or a drone, and it can be configured as a mobile base station. For terminal devices 120j that access RAN 100 through network element 120i, network element 120i is a base station; however, for base station 110a, network element 120i is a terminal device. RAN node 110 and terminal device 120 are sometimes referred to as communication devices, for example... Figure 1A Network elements 110a and 110b can be understood as communication devices with base station functions, while network elements 120a-120j can be understood as communication devices with terminal equipment functions.

[0109] In one possible scenario, RAN node 110 can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a base station in a future mobile communication system, or an access node in a WiFi system, etc. Figure 1A 110a), micro base stations or indoor stations (such as Figure 1A The RAN node 110 can be a relay node or donor node, or a wireless controller in a CRAN scenario. Optionally, the RAN node 110 can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network device in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of the RAN node 110 in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The RAN node 110 in this application can also be a logical node, logical module, or software capable of implementing all or part of the functions of the RAN node 110.

[0110] In another possible scenario, multiple RAN nodes 110 collaborate to assist terminal devices in achieving wireless access, with each RAN node 110 implementing a portion of the base station's functions. For example, a RAN node 110 can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. CUs and DUs can be configured separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio equipment or radio units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0111] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0112] The full name of O-CU can be O-RAN central unit or O-RAN control unit (O-RAN convergence unit, or O-RAN control unit). O-CU is used to implement the radio resource control (RRC) layer, packet data convergence protocol (PDCP) layer, service data adaptation protocol (SDAP) layer, and other control functions in the 3GPP standard.

[0113] The full name of O-CU-CP can be O-RAN central unit control plane or O-RAN control unit control plane (O-RAN aggregation unit control plane or O-RAN control unit control plane). Similar to CU-CP in the NR system, O-CU-CP is used to implement the functions of the RRC layer and the control plane functions of the PDCP layer.

[0114] The full name of O-CU-UP can be O-RAN central unit user plane or O-RAN control unit user plane (O-RAN aggregation unit user plane or O-RAN control unit user plane). Similar to CU-UP in the NR system, O-CU-UP is used to implement the functions of the SDAP layer and the user plane functions of the PDCP layer.

[0115] The full name of O-DU can be ORAN distributed unit. O-DU is based on lower-layer function partitioning and is used to implement the higher layers (closer to the MAC layer) of the radio link control (RLC) layer, media access control (MAC) layer, and physical layer (PHY) in the 3GPP standard. The higher-layer functions of the physical layer include one or more of the following: forward error correction (FEC) encoding / decoding, scrambling / descrambling, or modulation / demodulation.

[0116] The full name of O-RU can be ORAN radio unit. Based on low-layer function segmentation, it is used to implement the low-layer (near radio frequency) functions of the PHY and radio frequency functions in the 3GPP standard. The low-layer physical layer functions include one or more of the following: Fast Fourier Transform (FFT) / Inverse Fast Fourier Transform (iFFT), digital beamforming, or extraction and filtering of the physical random access channel (PRACH). It is similar to the transmission reception point (TRP) or remote radio head (RRH) in 3GPP, but includes the low-layer functions of the PHY, such as FFT / iFFT or PRACH extraction.

[0117] A non-real-time RAN intelligent controller (non-real-time RIC, or simply "non-real-time RIC") is sometimes also called a non-RT RIC or NRT RIC. It is used to implement non-real-time intelligent management of RAN functions. It can implement AI / ML workflows including model training and model updates, and guide applications / functions within the nRTRIC based on policies.

[0118] The near-real-time RAN intelligent controller (near-real-time RIC), sometimes also called near-RT RIC or nRT RIC, is used to achieve near-real-time intelligent management of the RAN. Through data collection and related operations on the E2 interface, it enables near-real-time control and optimization of O-RAN modules and resources.

[0119] The interfaces designed for NR RAN include NG, Xn, X2, E1, F1-C, and F1-U. Specifically: NG interface: The interface between NR RAN equipment (such as base stations, CUs, CU-CPs, or CU-UPs) and the NR core network; NG-u is the user plane NG interface, and NG-c is the control plane NG interface. Xn interface: The interface between NR RAN equipment (such as base stations, CUs, CU-CPs, or CU-UPs); Xn-u is the user plane Xn interface, and Xn-c is the control plane Xn interface. X2 interface: The interface between LTE RAN equipment; X2-u is the user plane X2 interface, and X2-c is the control plane X2 interface. In NR, the X2 interface is mainly used in E-UTRA-NR dual connectivity (EN-DC) scenarios, where the master station is an LTE RAN equipment connected to the LTE core network via the X2 interface. E1 interface: The interface between CU-CP and CU-UP. F1-C interface: The interface between CU-CP and DU. F1-U interface: The interface between CU-UP and DU.

[0120] For example, please see Figure 1B , Figure 1B This is a schematic diagram of an O-RAN system architecture provided in this application. Figure 1B This is just an illustration; the O-RAN system may also include... Figure 1B Other components besides those shown. For example... Figure 1BAs shown, the access network device (e.g., an eNB, gNB, or next-generation access network device) communicates with the core network elements in the CN via a backhaul link and with the terminal device via an air interface.

[0121] Specifically, the BBU in the access network device communicates with the core network elements in the CN via a backhaul link, and the RU in the access network device communicates with at least one terminal device via an air interface. The BBU communicates with at least one RU via a fronthaul link. The BBU and RU may or may not be co-located. The BBU includes at least one CU and at least one DU, which can communicate via at least one midhaul link.

[0122] Optionally, O-RAN can also incorporate artificial intelligence (AI).

[0123] Figure 1C This is a schematic diagram of another architecture of the O-RAN system provided in this application. For example... Figure 1C As shown, the communication system includes a RAN intelligent controller (RIC). For example, the RIC can be an AI module used to implement AI-related functions. RICs include near-real-time RICs (near-RT RICs) and non-real-time RICs (non-RT RICs). Non-real-time RICs primarily process non-real-time information, such as data that is not sensitive to latency, with latency in the order of seconds. Real-time RICs primarily process near-real-time information, such as data that is relatively sensitive to latency, with latency in the order of tens of milliseconds.

[0124] The aforementioned near real-time RIC is used for model training and inference. For example, it can be used to train an AI model and then use that model for inference. The near real-time RIC can obtain network-side and / or terminal-side information from RAN nodes (e.g., CU, CU-CP, CU-UP, DU, and / or RU) and / or terminal devices. This information can be used as training data or inference data. Optionally, the near real-time RIC can deliver the inference results to the RAN nodes and / or terminal devices. Optionally, inference results can be exchanged between CU and DU, and / or between DU and RU. For example, the near real-time RIC delivers the inference results to the DU, and the DU sends them to the RU.

[0125] The aforementioned non-real-time RIC is also used for model training and inference. For example, it can be used to train an AI model and then use that model for inference. The non-real-time RIC can obtain network-side and / or terminal-side information from RAN nodes (e.g., CU, CU-CP, CU-UP, DU, and / or RU) and / or terminal devices. This information can be used as training data or inference data, and the inference results can be delivered to the RAN nodes and / or terminal devices. Optionally, inference results can be exchanged between CU and DU, and / or between DU and RU; for example, the non-real-time RIC delivers the inference results to the DU, which then forwards them to the RU.

[0126] The aforementioned near real-time RIC and non-real-time RIC can also be configured as separate network elements. Optionally, the aforementioned near real-time RIC and non-real-time RIC can also be part of other devices. For example, the near real-time RIC can be set in the RAN node (e.g., in CU, DU), while the non-real-time RIC can be set in the OAM, cloud server, core network device, or other network device.

[0127] Figure 1D This diagram illustrates the network element functional division and protocol layer structure of an O-RAN device. In some examples, the CU (Core Unit) is a logical node carrying the RRC, SDAP, PDCP, and other control functions of the access network device. The CU connects to network nodes such as the core network through interfaces, which can be interfaces such as E2 interfaces. Optionally, the CU may have some core network functions. The CU (e.g., PDCP layer and higher layers) connects to the DU (e.g., RLC layer and lower layers) through interfaces, which can be interfaces such as F1 interfaces. In some examples, these interfaces (e.g., F1 interfaces) can provide control plane (C-Plane) and user plane (U-Plane) functions (e.g., interface management, system information management, UE context management, RRC message transmission, etc.). The F1 application (AP) protocol is the application protocol of the F1 interface, and in some examples, it defines the F1 signaling procedures. The F1 interface supports the control plane F1-C and the user plane F1-U.

[0128] In some examples, the CU can be split into CU-CP (control unit-control plane) and CU-UP (control unit-user plane). CU-CP is a logical node carrying the RRC layer and PDCP-C (control plane part of PDCP) layer, used to implement the CU's control plane functions. CU-CP can interact with network elements in the core network used to implement control plane functions. These network elements in the core network can be access and mobility function (AMF) network elements, such as the access and mobility management function (AMF) in a 5G system. AMF network elements are responsible for mobility management in the mobile network, such as terminal device location updates, terminal device registration with the network, and terminal device handover. CU-UP is a logical node carrying the SDAP layer and PDCP-U (user plane part of PDCP) layer, used to implement the CU's user plane functions. CU-UP can interact with network elements in the core network used to implement user plane functions. These network elements in the core network, such as the user plane function (UPF) in a 5G system, are responsible for data forwarding and receiving in terminal devices. The above CU and DU configurations are merely examples; the functions of the CU and DU can be configured as needed. For instance, the CU or DU can be configured to have more protocol layer functions, or only some protocol layer processing functions. For example, some RLC layer functions and protocol layer functions above the RLC layer can be placed in the CU, while the remaining RLC layer functions and protocol layer functions below the RLC layer can be placed in the DU. Furthermore, the functions of the CU or DU can be divided according to service type or other system requirements, such as by latency. Functions that require low latency can be placed in the DU, while functions that do not require low latency can be placed in the CU.

[0129] In some examples, a DU is a logical node that carries the RLC layer, medium access control (MAC) layer, higher physical layer (Higher PHY) layer, and other functions. In some examples, a DU can control at least one RU. The DU connects to the RU through interfaces, which can be fronthaul interfaces. In some examples, the Higher PHY layer includes the PHY layer processing, such as forward error correction (FEC) encoding and decoding, scrambling, modulation, and demodulation.

[0130] In some examples, the RU is a logical node that carries both lower physical layer (PHY) and radio frequency (RF) processing. In some examples, the RU can be a 3GPP TRP, a remote radio head (RRH), or other similar entity. In some examples, the Low-PHY includes PHY processing functions such as Fast Fourier Transform (FFT), Inverse Fast Fourier Transform (IFFT), digital beamforming, and filtering. The RU communicates with one or more terminal devices via a wireless link.

[0131] The DU and RU can be co-located or not. The DU and RU exchange control plane and user plane information via a fronthaul link through the Lower-Layer Split CUS-Plane (LLS-CUS) interface. LLS-CUS may include LLS-C and LLS-U interfaces providing the control plane (C-Plane) and user plane (U-Plane), respectively. In some examples, the control plane (C-Plane) refers to real-time control between the DU and RU. The DU and RU exchange management information via an LLS-M interface on the fronthaul link; the management plane (M-Plane) refers to non-real-time management operations between the DU and RU.

[0132] DU and RU can cooperate to implement the functions of the PHY layer. A DU can be connected to one or more RUs. The functions of DU and RU can be configured in various ways depending on the design. For example, a DU can be configured to implement baseband functions, and an RU can be configured to implement mid-RF functions. Another example is that a DU can be configured to implement higher-level functions in the PHY layer, and an RU can be configured to implement lower-level functions in the PHY layer, or to implement both lower-level and RF functions. Higher-level functions in the physical layer can include a portion of the physical layer's functions that are closer to the MAC layer, while lower-level functions in the physical layer can include another portion of the physical layer's functions that are closer to the mid-RF side.

[0133] Figure 1EThese are schematic diagrams illustrating the structures of two base stations exemplarily provided in embodiments of this application. For example, a base station may include two CU-UPs and one DU. The two CU-UPs are connected via an E1 interface. One CU-UP includes an RRC layer and a PDCP-C layer, while the other CU-UP includes an SDAP layer and a PDCP-U layer. The two CU-UPs are connected to the DU via F1-C and F1-U, respectively. The DU includes an RLC layer, a MAC layer, and a PHY layer. Alternatively, a base station may include two DUs and one CU. The DU includes an RLC layer, a MAC layer, and a PHY layer. The two DUs are connected to the CU via F1, respectively. The CU includes an RRC layer, an SDAP layer, and a PDCP layer.

[0134] Terminal equipment refers to devices or modules that access the aforementioned communication systems and possess corresponding communication functions. Terminals can also be called terminals, user equipment (UE), user devices, access terminals, user units, user stations, mobile stations, mobile stations (MS), remote stations, remote terminals, mobile devices, user terminals, terminal units, terminal stations, terminal devices, wireless communication equipment, user agents, or user devices, etc. Terminal equipment typically contains communication modules, circuits, or chips that perform the corresponding communication functions. It may also be configured with program instructions for performing these functions. Terminal equipment can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), the Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, transportation vehicles with wireless communication capabilities, communication modules, roadside units (RSUs) with terminal device functions, etc. The embodiments of this application do not limit the form of the terminal device.

[0135] For ease of description, the following description uses a base station as an example of RAN node 110. Base stations and terminal equipment can be fixed or mobile. Base stations and terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminal equipment.

[0136] The roles of base stations and terminal devices can be relative, for example, Figure 1A The helicopter or drone 120i can be configured as a mobile base station. For terminal devices 120j that access the wireless access network 100 via 120i, terminal device 120i is a base station; however, for base station 110a, 120i is a terminal device, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol; in this case, 120i is also a base station relative to 110a. Therefore, both base stations and terminal devices can be collectively referred to as communication devices. Figure 1A The 110a and 110b in the text can be referred to as communication devices with base station functions. Figure 1A The 120a-120j in the text can be referred to as communication devices with terminal equipment functions.

[0137] Communication between base stations and terminal devices, between base stations, and between terminal devices can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0138] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal device can be executed by modules (such as chips or modems) within the terminal device, or by a device that includes terminal device functions.

[0139] In this application, the base station sends downlink signals or downlink information to the terminal device, with the downlink information carried on the downlink channel; the terminal device sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. To communicate with the base station, the terminal device needs to establish a radio connection on a cell controlled by the base station. The cell with which the terminal device has established a radio connection is called the serving cell of the terminal device. When the terminal device communicates with this serving cell, it is also subject to interference from signals from neighboring cells.

[0140] In this application, "sending information" can be understood as one device sending information to another device, or it can also be understood as one logical module within a device sending information to another logical module. For example, "base station sending information" can be understood as the base station sending information to another device (such as a terminal device), or it can be understood as logical module 1 in the base station sending information to logical module 2 in the base station.

[0141] In this application, "receiving information" can be understood as one device receiving information from another device, or it can also be understood as a logical module within a device receiving information from another logical module. For example, "base station receiving information" can be understood as the base station receiving information from another device (such as a terminal device), or it can be understood as logical module 1 in the base station receiving information from logical module 2 in the base station.

[0142] The communication between different devices involved in this application can refer to direct communication between different devices (i.e., without the need for relaying or forwarding by other devices), or communication between different devices through other devices (i.e., requiring relaying or forwarding by other devices), or communication between a functional unit within a device and other devices through another functional unit. In other words, "sending information to… (e.g., a terminal device)" or the relevant illustrations in the accompanying drawings can be understood as the destination of the information being the terminal device. This can include sending information directly or indirectly to the terminal device. "Receiving information from… (e.g., a terminal device)" or "receiving information from… (e.g., a terminal device)" or "receiving information sent (e.g., by a terminal device)" or the relevant illustrations in the accompanying drawings can be understood as the source of the information being the terminal device. This can include receiving information directly or indirectly from the terminal device. Information may undergo necessary processing between the source and destination, such as format changes, digital-to-analog conversion, amplification, filtering, etc., but the destination can understand the valid information from the source. Similar expressions in this application can be understood in a similar way, and will not be elaborated further here.

[0143] The technical terms and related technologies involved in this application are described below.

[0144] 1. Mobile robustness optimization (MRO) mechanism

[0145] To mitigate mobility anomalies caused by improper network parameter settings, such as connection failures (which can include handover failures and radio link failures), unnecessary cross-system handovers, cross-system ping-pong handovers, failures to add / change primary / secondary cells, failures to provide voice fallback across systems, failures to recover fast primary cell groups, suboptimal handovers, and suboptimal addition / changes of primary / secondary cells, the system currently supports a mobility robustness optimization mechanism to detect and correct these mobility anomalies.

[0146] When a terminal device experiences the aforementioned mobility anomaly, it reports mobility-related information (also known as a MRO report) to the network. The network device can then autonomously analyze and optimize mobility parameters based on the information reported by the terminal device. For example, an MRO report may include an RLF report (Radio Link Failure Report), SCG Failure Information (Secondary Cell Group Failure Information), an SHR report (Successful Handover Report), and an SPR report (Successful PSCell Addition / Change Report).

[0147] The MRO mechanism supports RAN analysis and correction of connection failures, such as detecting connection failure types like premature handover, late handover, or handover to the wrong cell. One method is RAN based on the RLF report reported by the UE, and the other is information exchange between RANs and between CUs and DUs, with the network side analyzing the information exchanged between nodes.

[0148] This application can perform mobility parameter optimization analysis based on time lead information, which can reduce mobility anomaly issues and improve the MRO mechanism.

[0149] 2. LTM

[0150] In 3GPP Release 17 and earlier versions, several different L3 handover types were introduced, including basic handover, CHO, and DAPS. In L3 handover, the change of serving cell is triggered by L3 measurements and is completed based on RRC signaling (including RRC reconfiguration messages with synchronization cells). The change of serving cell can be a primary cell change or a primary-secondary cell change. L3 handover requires reconfiguration of higher layers (i.e., RRC / PDCP layer) and / or reset of lower layers (e.g., MAC layer, physical layer). Therefore, compared to beam handover without explicit RRC signaling, L3 handover results in longer latency, greater signaling overhead, and longer interruption latency.

[0151] LTM was introduced in 3GPP Release 18 to reduce mobility latency. LTM enables serving cell changes based on L1 / L2 signaling. Specifically, when the gNB-DU receives the L1 measurement report from the UE, the gNB-DU instructs the UE to change the serving cell (such as from the source cell to the target cell) through a handover command (also known as a cell switch command) carried by the MAC CE. This handover command indicates a gNB candidate cell configuration, which is one of at least one candidate cell configuration that the gNB has sent to the UE in advance via RRC signaling.

[0152] LTM supports intra-DU and inter-DU mobility managed under the same CU (the source and target cells during the handover process belong to the same DU or different DUs). Furthermore, it supports continuous LTM, which refers to the UE performing multiple handovers between LTM candidate cells without requiring network-side RRC reconfiguration during the process.

[0153] Currently, under the LTM mechanism, there are scenarios where TA (Task Transfer) causes LTM to fail, as well as scenarios where TA can potentially cause LTM to fail. These will be discussed below. Figure 2A and Figure 2B The two scenarios described above will be introduced.

[0154] Please see Figure 2A The process includes the following steps:

[0155] Step 1: The network device (i.e., the source DU) sends candidate cell configurations to the UE. The candidate cell configurations may include the configurations of one or more candidate cells. For example, the network device (such as a gNB) pre-configures the configurations of one or more candidate cells to the UE via an RRC reconfiguration message.

[0156] Step 2: The source DU instructs the UE to initiate TA acquisition from the target DU.

[0157] For example, a source DU (the DU to which the source cell belongs) can instruct the UE to initiate TA acquisition (or early TA acquisition) to one or more candidate cells, where the candidate DU is the DU to which the candidate cell belongs, and one or more candidate cells include the target DU. The target DU is used as an example here for illustration.

[0158] Optionally, the source DU can instruct the UE to initiate TA acquisition to the target DU multiple times and receive TA values ​​from the target DU multiple times (i.e., there are multiple TA information transfers as shown in steps 2 and 3).

[0159] Step 3: The target DU instructs the source DU to TA through the CU.

[0160] For example, after receiving the random access preamble sent by the UE, the candidate DU indicates the TA to the source DU through the CU. The candidate cell includes the target DU. Here, the target DU is used as an example for explanation.

[0161] Step 4: The source DU performs LTM handover decision.

[0162] Optionally, the source DU can perform handover decisions based on the L1 measurement report and / or auxiliary information indicated by the CU reported by the UE. For example, the auxiliary information indicated by the CU may include information such as L3 measurement results or target cell (or LTM target cell).

[0163] For example, if the source DU performs an LTM handover decision and determines to perform an LTM handover, the source DU can perform the following step 5.

[0164] Step 5: The source DU sends an LTM handover command to the UE.

[0165] For example, the LTM handover command is used to instruct the UE to hand over from the source cell to the target cell.

[0166] For example, the source DU can send an LTM handover command to the UE via the Layer 2 MAC CE to indicate the target cell configuration. The LTM handover command may also include the target cell's TA and beam information to enable the UE to perform RA-less (random access-free) access. The beam information is included in the transmission configuration indicator state (TCI state) information, which can be used to indicate to the UE the quasi-co-location reference signal (wherein the reference signal can be an SSB index or a CSI-RS index) and the quasi-co-location type.

[0167] Step 6: The source DU sends a handover notification message to the target DU (the DU to which the target cell belongs) through the CU. This message may include target cell information and beam information, and may also include the TA of the candidate cell for continuous LTM.

[0168] Step 7: UE fails to perform RA-less LTM handover. One possible reason for UE failure to perform RA-less LTM handover is that the TA value used during RACH-less handover is invalid.

[0169] Step 8: The UE accesses the target cell via random access.

[0170] For example, the UE performs cell selection, selects the target cell indicated in step 4 above, attempts to access the target cell in a random access manner, and successfully accesses the target cell based on the TA value indicated by the network side (target DU) response.

[0171] Please see Figure 2B The process includes the following steps:

[0172] Figure 2B Steps 1 to 6 can be found in [the original text]. Figure 2A Steps 1 to 6 in the process. Among them, the LTM switching command in step 5 includes the TA for RA-less LTM switching.

[0173] Step 7: The UE successfully performs RA-less LTM handover, that is, the UE successfully sends the first uplink data packet based on the TA included in the LTM handover command.

[0174] Step 8: The target DU instructs the UE to adjust the TA value. For example, the target DU can instruct the UE to adjust the TA value via the MAC CE command, such as instructing the UE to adjust the TA value to TA value5. The UE then sends subsequent uplink data packets based on TA value5.

[0175] For example, the target DU can determine the TA value of the UE by measuring the UE's uplink transmission. If a particular UE needs calibration, the target DU can send a Timing Advance Command to that UE, requesting it to adjust its uplink transmission TA. For example, this Timing Advance Command is sent to the UE via the Timing Advance Command MAC control element.

[0176] Optionally, the TA adjustment indicated by the target DU to the UE can be after the first uplink data packet transmission, after the first N uplink data packet transmissions, or after a specific preset period of time; this scheme does not impose any restrictions.

[0177] Step 9: The UE performs uplink transmission based on the adjusted TA value. For example, if the target DU instructs the UE to adjust the TA value to TAvalue5, then the UE sends subsequent uplink data packets based on TA value5.

[0178] The inventors of this application have analyzed the above two scenarios as follows: After receiving the TA value from the candidate / target DU, the source DU is responsible for managing the validity period of the TA and determining whether to indicate it to the UE. Therefore, the TA of the UE when performing RACH-less LTM handover has the following situations: 1) The source DU may instruct the UE to initiate an early TA to the target DU multiple times, and therefore may receive the TA value from the target DU multiple times. The TA value indicated by the source DU to the UE can be the latest TA value or other valid TA values; 2) After the source DU considers that the TA provided by the candidate DU has expired, it does not indicate the TA value to the UE. The UE performs RACH-less access based on the TA value it measures itself; 3) The source DU does not trigger the UE to initiate an early TA, and the target DU does not receive the UE's early TA request.

[0179] Analysis revealed that the inventors of this application discovered that the CU and target DU cannot determine which TA value was used when the UE failed to perform RACH-less access or when the TA timeout was too fast. When the UE re-accesses the LTM target cell via random access, the source DU and CU cannot determine the TA value used by the UE for re-access. Therefore, since the CU, target DU, and source DU cannot obtain the TA value used by the UE for two accesses to the LTM target cell or the TA value used by the UE for two uplink data packets sent in the target cell, TA problem detection and analysis are impossible.

[0180] In view of this, embodiments of this application provide a communication method and apparatus. The method can enable at least one of the CU, target DU, and source DU to obtain the TA value used by the UE before and after accessing the same target cell, or the TA value used by the UE twice when sending uplink data packets in the target cell. It enables the network side to detect invalid TA events and optimizes the TA management mechanism, including mobility parameters such as TA acquisition timing and TA validity period relationship.

[0181] Based on the system architecture described above, the communication method provided in the embodiments of this application will be described below. Optionally, the communication method provided in the embodiments of this application (such as...) is allowed to... Figures 3 to 8 The steps in any of the communication methods shown can be adjusted appropriately, for example, by adjusting the order of the steps, adding or removing steps, etc.

[0182] Figure 3 This is a flowchart illustrating a communication method provided in an embodiment of this application.

[0183] In this application embodiment, the steps performed by the first communication device can also be performed by a module of the first communication device (e.g., a chip, chip system, integrated circuit, or control unit); in this application embodiment, the steps performed by the fourth communication device can also be performed by a module of the fourth communication device (e.g., a chip, chip system, integrated circuit, or control unit).

[0184] like Figure 3 As shown, the communication method may include some or all of the following steps:

[0185] Step S301: The fourth communication device sends a first indication information to the first communication device. The first indication information is used to indicate the first time advance information. The first time advance information is the time advance information used by the terminal device to perform the first uplink transmission when it accesses the first cell in a non-random access manner.

[0186] Accordingly, the first communication device receives first indication information sent from the fourth communication device. For example, the first indication information may be included in one or more of the following: a CU-DU cell switch notification message, a DU-CU cell switch notification message, an uplink RRC message transfer message (UL RRC Message Transfer Message), and an uplink RRC message transfer message (DL RRC Message Transfer Message). The fourth communication device may send the first indication information to the first communication device via the second communication device.

[0187] It should be noted that in this application, Figures 3 to 6 The fourth communication device in Figures 7 to 8 The third communication device can be two separate communication devices (e.g., two separate DUs); or, the third and fourth communication devices can be the same communication device (e.g., the same DU), meaning that this communication device can perform... Figures 3 to 6 The fourth communication device in the middle has all or part of its functions, and can perform Figures 3 to 6 All or part of the functions of the third communication device in the system.

[0188] For example, the first communication device is the DU (or target DU) corresponding to the first cell (or target cell), and the fourth communication device is the DU (or source DU) corresponding to the source DU (or second cell) where the terminal device was located before accessing the first cell. For example, the fourth communication device sending the first indication information to the first communication device can be: the source DU sends the first indication information to the target DU through the CU, such as the source DU sending the first indication information to the CU, and then the CU sending the first indication information to the target DU. A specific implementation of this scenario can be exemplarily described below. Figure 4 Examples will not be elaborated here.

[0189] Optionally, the first indication information is used to indicate whether the second cell sends a timing advance to the terminal device or does not send a timing advance to the terminal device, and / or the first indication information is used to indicate the timing advance indicated by the second cell to the terminal device (for ease of description, it is referred to as the first timing advance), wherein the second cell is the source cell that indicates the terminal device to access the first cell in a manner that avoids random access.

[0190] For example, the first indication information is used to indicate that the second cell sends a time advance to the terminal device; or, the first indication information is used to indicate that no time advance is sent to the terminal device; or, the first indication information is used to indicate that the second cell indicates a first time advance to the terminal device; or, the first indication information is used to indicate that the second cell sends a time advance to the terminal device, and the first indication information is also used to indicate a first time advance, where the first time advance is the time advance that the second cell sends to the terminal device.

[0191] For example, the first indication information is used to indicate that the LTM handover command sent by the second cell to the terminal device includes a time advance; or, the first indication information is used to indicate that the LTM handover command sent by the second cell to the terminal device does not include a time advance; or, the first indication information is used to indicate that the LTM handover command includes a first time advance; or, the first indication information is used to indicate that the LTM handover command sent by the second cell to the terminal device includes a time advance, and the first indication information is used to indicate that the time advance included in the LTM handover command is a first time advance.

[0192] Alternatively, the handover notification message may be used to indicate that the LTM handover command sent by the second cell to the terminal device includes a time advance; or, the first indication information may be used to indicate that the LTM handover command sent by the second cell to the terminal device does not include a time advance; or, the first indication information may be used to indicate that the LTM handover command includes a first time advance; or, the first indication information may be used to indicate that the LTM handover command sent by the second cell to the terminal device includes a time advance, and the first indication information may be used to indicate that the time advance included in the LTM handover command is a first time advance.

[0193] For example, the handover notification message includes a first field. If the value of the first field is 0, the field is used to indicate that the LTM handover command sent by the second cell to the terminal device does not include a time advance. Alternatively, if the value of the first field is 1, the field is used to indicate that the LTM handover command sent by the second cell to the terminal device includes a time advance. And / or, the handover notification message includes a second field. If the second field includes a time advance, the time advance is the time advance included in the LTM handover command sent by the second cell to the terminal device (i.e., the specific value of the first time advance). If the handover notification message does not include the second field, i.e., when the time advance is missing, the absence of the second field is used to implicitly indicate that the LTM handover command sent by the second cell to the terminal device does not include a time advance.

[0194] For example, the first instruction information may be a first field and / or a second field. It should be noted that the first field and / or the second field may be any of the possible forms of the first instruction information described above, and the first instruction information may also be in other forms, which are not limited in this application.

[0195] Step S302: The first communication device performs mobility parameter optimization analysis based on the first instruction information.

[0196] Optionally, the first communication device may perform mobility parameter optimization analysis based on the first indication information and the second indication information; or, it may perform mobility parameter optimization analysis based on the first indication information and the third indication information. For example, the process of the first communication device performing mobility parameter optimization analysis is as follows: The first communication device identifies / determines whether there is a problem with the timing advance used during random access exemption being invalid or failing too quickly. That is, it determines whether the first timing advance is invalid based on whether the difference between the first timing advance and the second timing advance is too large, or it determines whether the first timing advance fails too quickly based on whether the timing advance adjustment by the terminal device (from the first uplink timing advance to the third timing advance) occurs within a very short time after the first uplink transmission (such as within a preset period of time). If the first timing advance is invalid or fails too quickly, other communication devices are notified of the timing advance problem and related information, such as by sending the first information, in order to optimize the timing advance acquisition and management process. The second indication information is used to instruct the terminal device to use the second timing advance information (or second timing advance) to access the first cell based on random access. Access to the first cell based on random access is triggered by the failure of access to the first cell without random access. The third indication information is used to instruct the terminal device to use the third timing advance information (or third timing advance) to execute the second uplink transmission after successfully accessing the first cell, or to instruct the terminal device to execute the third timing advance information to execute the second uplink transmission after a timing advance adjustment occurs.

[0197] In other words, there are two possible scenarios for step S302. Scenario 1 is: if the terminal device fails to access the first cell by avoiding random access and instead accesses the first cell by random access, then the first communication device can perform mobility parameter optimization analysis based on the first indication information and the second indication information. In other words, the first communication device performs mobility parameter analysis based on the first timing advance information and the second timing advance information.

[0198] Scenario 2 is as follows: The terminal device successfully accesses the first cell using a method to avoid random access. The first communication device can perform mobility parameter optimization analysis based on the first indication information and the third indication information. Alternatively, the first communication device can perform mobility parameter optimization analysis based on the first timing advance information and the third timing advance information. For example, the specific implementations of Scenario 1 and Scenario 2 can be found in [link to example]. Figure 4 The relevant content for scenarios 1 and 2.

[0199] Optionally, the second indication information is used to indicate a second time advance, which is the time advance used by the terminal device to access the first cell based on random access. For example, the second indication information may include a numerical value of the second time advance.

[0200] Optionally, the third indication information is used to indicate a third timing advance, which is the timing advance used by the terminal device to perform the second uplink transmission after successfully accessing the first cell, or it is used to indicate the third timing advance information used by the terminal device to perform the second uplink transmission after a timing advance adjustment has occurred. For example, the second indication information may include a numerical value of the second timing advance.

[0201] Optionally, the first communication device may further send first information, wherein the first information includes at least one of the following: the failure to access the first cell without random access is caused by an invalid time advance, a first time advance, a second time advance, or a first difference, wherein the first difference is the difference between the first time advance and the second time advance, the first time advance is the time advance used by the terminal device to perform the first uplink transmission when accessing the first cell without random access, and the second time advance is the time advance used by the terminal device to access the first cell based on random access.

[0202] above Figure 3 The method embodiments shown include many possible implementation schemes, which will be discussed below. Figure 4 Some of the implementation schemes will be illustrated with examples. It should be noted that... Figure 4 For any unexplained related concepts, operations, or logical relationships, please refer to [link / reference]. Figure 3 The corresponding description in the illustrated embodiment.

[0203] In this application, Figure 4 The illustrated embodiment can be considered as a standalone embodiment. Figure 4 The embodiments shown can all be implemented without relying on Figure 3 The technical solution; Figure 4 Some of the steps in the illustrated embodiments can also be used as separate embodiments.

[0204] Figure 4 This is a schematic diagram of another communication method provided in an embodiment of this application. Figure 4 The method is exemplified by using the first communication device as the target DU, the fourth communication device as the source DU, and the terminal device as the UE. The method includes some or all of the following steps:

[0205] Step S401: The source DU sends the candidate cell configuration to the UE. Correspondingly, the UE receives the candidate cell configuration from the source DU.

[0206] The candidate cell configuration may include the configuration of one or more candidate cells. For example, a network device (such as a gNB) pre-configures the configuration of one or more candidate cells to the UE via an RRC reconfiguration message.

[0207] Alternatively, the source cell sends candidate cell configuration to the UE, where the source cell is the cell to which the source DU belongs.

[0208] Step S402: The source DU instructs the UE to initiate TA acquisition from the target DU.

[0209] For example, the source DU can instruct the UE to initiate TA acquisition (or early TA acquisition) to one or more candidate cells, where the candidate DU is the DU to which the candidate cell belongs, and the target DU can be any one of one or more candidate cells.

[0210] Optionally, the source DU can instruct the UE to initiate TA acquisition to the target DU multiple times and receive TA values ​​from the target DU multiple times (i.e., there are multiple TA information transfers as shown in steps S402 and S403).

[0211] Step S403: The target DU instructs the source DU to TA through the CU.

[0212] Optionally, the source DU may receive TA values ​​from the target DU multiple times. For example, the target DU may indicate to the source DU via the CU that the TA includes TAvalue1, TAvalue2, and TA value3, etc.

[0213] Step S404: The source DU performs an LTM handover decision.

[0214] Optionally, the source DU can perform handover decisions based on the L1 measurement report and / or auxiliary information indicated by the CU reported by the UE. For example, the auxiliary information indicated by the CU may include L3 measurement results or information about the target cell.

[0215] For example, if the source DU determines to perform an LTM switch, the source DU may perform the following step S405.

[0216] Step S405: The source DU sends an LTM handover command to the UE. The LTM handover command instructs the UE to hand over from the source cell to the target cell. Correspondingly, the UE receives the LTM handover command from the source DU.

[0217] Optionally, the LTM handover command may include a time advance for the UE to perform random access-free operation, or it may not include the LTM handover command. For example, the LTM handover command may include TAvalue1, which is used by the UE to perform random access-free operation.

[0218] For example, the source DU can send an LTM handover command to the UE via the Layer 2 MAC CE to indicate the target cell configuration. The LTM handover command may also include the target cell's TA and beam information to enable the UE to perform RA-less access. The beam information is included in the transmission configuration indicator state (TCI state) information, which can be used to indicate to the UE the quasi-co-location reference signal (wherein the reference signal can be an SSB index or a CSI-RS index) and the quasi-co-location type.

[0219] Step S406: The source DU sends a handover notification message to the target DU via the CU. This handover notification message includes first indication information. The target DU is the DU to which the target cell belongs. Correspondingly, the source DU receives the handover notification message from the target DU via the CU.

[0220] For example, the first indication information is used to indicate at least one of the following (or, the handover notification message includes at least one of the following): whether the LTM handover command indicates a TA, and the TA value indicated in the LTM handover command (also known as the TA value of the LTM target cell sent to the UE).

[0221] For example, if the LTM handover command includes TA value1, and TA value1 is used by the UE to perform random access-free operation, then the first indication information may include TA value1, or the first indication information may be TA value1, or the first indication information may be used to indicate TA value1.

[0222] One possible approach is to implicitly indicate whether the LTM handover command indicated a TA by whether the handover notification message includes the TA value indicated in the LTM handover command. For example, the absence of the TA value indicated in the LTM handover command in the handover notification message implicitly indicates that the LTM command did not send a TA value to the UE, while the presence of the TA value indicated in the LTM handover command not only indicates the specific TA value but also implicitly indicates that the LTM sent a TA to the UE.

[0223] Optionally, the handover notification message may also include target cell information and beam information, and may also include the TA of the candidate cell for continuous LTM.

[0224] Step S407: The UE performs RA-less LTM handover. If the handover is successful, proceed to Case 1; otherwise, proceed to Case 2.

[0225] Optionally, after the UE receives the above LTM handover command, it performs an LTM handover. At this time, there are two possibilities: the UE fails to perform the RA-less LTM handover or the UE performs the RA-less LTM handover successfully. If the handover fails, the subsequent steps can refer to the following case 1 (i.e., steps S408 and S409). If the handover is successful, the subsequent steps can refer to the following case 2 (i.e., steps S410 and S412).

[0226] Step S408: The UE accesses the target cell via random access based on the second indication information indicated by the target DU. The second indication information indicates the TA value, such as TAvalue5.

[0227] For example, the UE performs cell selection, selects the target cell indicated in step 4 above, attempts to access the target cell in a random access manner, and successfully accesses the target cell based on the TA value indicated by the target DU response (i.e. the TA value indicated by the second indication information).

[0228] Step S409: The target DU performs mobility parameter optimization analysis based on the first indication information.

[0229] For example, the target DU performs TA validity analysis based on the first and second indication information mentioned above to detect invalid TA events.

[0230] Step S410: The target DU instructs the UE to adjust the TA value. For example, the target DU can instruct the UE to adjust the TA value via MAC CE command, such as instructing the UE to adjust the TA value to TAvalue5, and the UE will send subsequent uplink data packets based on TAvalue5.

[0231] For example, the target DU can determine the TA value of the UE by measuring the UE's uplink transmission. If a particular UE needs calibration, the target DU can send a Timing Advance Command to that UE, requesting it to adjust its uplink transmission TA. This Timing Advance Command is sent to the UE via the Timing Advance Command MAC control element.

[0232] Optionally, the TA adjustment indicated by the target DU to the UE can be after the first uplink data packet transmission, after the first N uplink data packet transmissions, or after a specific preset period of time; this scheme does not impose any restrictions.

[0233] Step S411: The UE performs uplink transmission based on the adjusted TA value. For example, if the target DU instructs the UE to adjust the TA value to TA value5, then the UE sends subsequent uplink data packets based on TA value5.

[0234] Step S412: The target DU performs mobility parameter optimization analysis based on the first indication information.

[0235] For example, the target DU performs mobility parameter optimization analysis based on the first indication information and the third indication information. The first indication information is the TA value used by the UE to perform the first uplink transmission, and the third indication information is used to indicate the adjusted TA value (such as TA value5). For example, the third indication information can be TA value5. It should be noted that TA value5 in case 1 and TA value5 in case 2 are only the TA value number or the TA value instance number. The TA value instances they refer to can be the same or different, and this application does not limit this.

[0236] Step S413: The target DU sends first information to the source DU. Correspondingly, the source DU receives the first information from the target DU.

[0237] Step S413 is an optional step.

[0238] For example, the first information may include at least one of the following: invalid TA, TA value1, TA value5, or TA difference. Wherein, invalid TA may be determined by the target DU based on step S611; TA value1 may be the TA value carried by the LTM switching command (i.e., the TA value indicated by the second indication information); TA value5 may be TA value5 in case 1 (i.e., the TA value indicated by the second indication information) or TA value5 in case 2 (i.e., the TA value indicated by the third indication information); TA difference may be the difference between TA value1 and TA value5.

[0239] For example, after the steps of Case 1 or Case 2 above are completed, the target DU sends the first information to the source DU via the CU.

[0240] Optionally, after the steps of Case 1 or Case 2 above are completed, the specific content of the first message sent by the target DU to the source DU may be the same or different.

[0241] For example, after the steps in Case 1 are completed, the first information sent by the target DU to the source DU can be an invalid TA, TA value1, TA value5 (second indication information), or TA difference.

[0242] For example, after the execution of step 2 above, the first information sent by the target DU to the source DU can be TAvalue1, TA value5 (third indication information), or TA difference.

[0243] Figure 5 This is a flowchart illustrating another communication method provided in an embodiment of this application.

[0244] In this application embodiment, the steps performed by the second communication device can also be performed by a module of the second communication device (e.g., a chip, chip system, integrated circuit, or control unit); in this application embodiment, the steps performed by the fourth communication device can also be performed by a module of the fourth communication device (e.g., a chip, chip system, integrated circuit, or control unit); in this application embodiment, the steps performed by the fifth communication device can also be performed by a module of the fifth communication device (e.g., a chip, chip system, integrated circuit, or control unit).

[0245] like Figure 5 As shown, the communication method may include some or all of the following steps:

[0246] Step S501: The fourth communication device sends a first indication information to the second communication device. The first indication information is used to indicate the first time advance information. The first time advance information is the time advance information used by the terminal device to perform the first uplink transmission when it accesses the first cell in a non-random access manner.

[0247] Correspondingly, the second communication device receives the first instruction information sent by the fourth communication device.

[0248] Optionally, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to instruct the terminal device to send a first timing advance, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0249] For example, the first indication information is included in the handover notification message (DU-CU CELL SWITCHNOTIFICATION message), the uplink RRC message transfer message (UL RRC MESSAGE TRANSFER message), or the access and mobility indication message (DU-CU Access and Mobility Indication message), wherein the first indication information is used to indicate whether the LTM handover command sent by the second cell to the terminal device includes a timing advance, and / or the first timing advance included in the LTM handover command, and the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0250] Step S502: The fifth communication device sends second information to the second communication device. The second information includes second indication information or third indication information. The second indication information is used to instruct the terminal device to use second timing advance information to access the first cell based on random access. Access to the first cell based on random access is triggered by the failure of access to the first cell without random access. The third indication information is used to instruct the terminal device to use third timing advance information to execute the second uplink transmission after successfully accessing the first cell without random access.

[0251] Correspondingly, the second communication device receives the second information sent by the fifth communication device.

[0252] For example, the second information is included in the handover success message, the uplink RRC message transfer message, or the DU-CU Access and Mobility Indication message. Optionally, the second information also includes an identifier for identifying the terminal device. For example, when the second information is sent via the handover success message or the uplink RRC message transfer message, the identifier for identifying the terminal device is the interface identifier (F1AP ID) assigned to the terminal device by the second and fifth communication devices; when the second message is sent via the Access and Mobility Indication message, the identifier for identifying the terminal device is the Cell Radio Network Temporary Identifier (C-RNTI) assigned to the terminal device by the first or second cell. For example, the second communication device can be a CU, the fifth communication device can be the DU (or target DU) corresponding to the first cell (or target cell), and the fourth communication device can be the DU (or source DU) corresponding to the source DU (or second cell) where the terminal device was located before accessing the first cell. For example, the specific implementation in this scenario can be found below. Figure 6 Examples will not be elaborated here.

[0253] Optionally, the second information may also include an identifier for identifying the terminal device.

[0254] It should be noted that in this application, Figures 3 to 4 The first communication device in Figures 5 to 8 The fifth communication device can be two separate communication devices (e.g., two separate DUs); or, the first and fifth communication devices can be the same communication device (e.g., the same DU), meaning that this communication device can perform... Figures 3 to 4 The fourth communication device in the middle has all or part of its functions, and can perform Figures 5 to 8 All or part of the functions of the third communication device in the system.

[0255] Step S503: The second communication device performs mobility parameter optimization analysis based on the first indication information and the second information, or the second communication device sends the first indication information and / or the second information.

[0256] In one possible implementation, the second communication device may further send first information, wherein the first information includes at least one of the following: the failure to access the first cell without random access is caused by an invalid timing advance, a first timing advance, a second timing advance, or a first difference, wherein the first difference is the difference between the first timing advance and the second timing advance, the first timing advance is the timing advance used by the terminal device to perform the first uplink transmission when accessing the first cell without random access, and the second timing advance is the timing advance used by the terminal device to access the first cell based on random access.

[0257] For example, the process of the second communication device performing mobility parameter optimization analysis is as follows: The second communication device identifies / determines whether there is an issue with the timing advance used during random access-free access being invalid or failing too quickly. Specifically, it determines whether the first timing advance is invalid based on whether the difference between the first timing advance and the second timing advance is too large, or it determines whether the first timing advance fails too quickly based on whether the timing advance adjustment by the terminal device (from the first uplink timing advance to the third timing advance) occurs within a very short time after the first uplink transmission (such as within a preset period of time). If the first timing advance is invalid or fails too quickly, other communication devices are notified of the timing advance issue and related information so that the timing advance acquisition and management process can be optimized.

[0258] In another possible implementation, the second communication device sends a first instruction message and / or a second message to the fourth communication device.

[0259] For example, the first indication information may include one or more of the following: a handover notification message (CU-DU CELL SWITCHNOTIFICATION message), a downlink RRC message transfer message (DL RRC MESSAGE TRANSFER message), or an access and mobility indication message.

[0260] For example, the second information may include one or more of the following: a downlink RRC message transfer message (DL RRC MESSAGETRANSFER message) or an access and mobility indication message (Access and Mobility Indication message). For example, the access and mobility indication message sent by the second communication device to the fourth communication device may include one or more of the following: first indication information, second information, and a radio link failure report (RLF report) corresponding to the terminal device.

[0261] above Figure 5 The method embodiments shown include many possible implementation schemes, which will be discussed below. Figure 6 Some of the implementation schemes will be illustrated with examples. It should be noted that... Figure 6 For any unexplained related concepts, operations, or logical relationships, please refer to [link / reference]. Figure 5 The corresponding description in the illustrated embodiment.

[0262] In this application, Figure 6 The illustrated embodiment can be considered as a standalone embodiment. Figure 6 The embodiments shown can all be implemented without relying on Figure 5 The technical solution; Figure 6 Some of the steps in the illustrated embodiments can also be used as separate embodiments.

[0263] Figure 6 This is a schematic diagram of another communication method provided in an embodiment of this application. Figure 6 The method is exemplified by using the second communication device as the CU, the fifth communication device as the target DU, the fourth communication device as the source DU, and the terminal device as the UE. The method includes some or all of the following steps:

[0264] Steps S601 to S605 can be exemplarily referred to in the content of steps S401 to S405 above, and will not be repeated here.

[0265] Step S606: The source DU sends a handover notification message to the CU, the handover notification message including first indication information. Correspondingly, the CU receives the handover notification message from the source DU.

[0266] For example, the first indication information is used to indicate at least one of the following: whether the LTM handover command indicated a TA, and the TA value indicated in the LTM handover command (also known as the TA value of the LTM target cell sent to the UE).

[0267] For example, if the LTM handover command includes TA value1, and TA value1 is used by the UE to perform random access-free operation, then the first indication information may include TA value1, or the first indication information may be TA value1, or the first indication information may be used to indicate TA value1.

[0268] One possible approach is to implicitly indicate whether the LTM handover command indicated a TA by whether the handover notification message includes the TA value indicated in the LTM handover command. For example, the absence of the TA value indicated in the LTM handover command in the handover notification message implicitly indicates that the LTM command did not send a TA value to the UE, while the presence of the TA value indicated in the LTM handover command not only indicates the specific TA value but also implicitly indicates that the LTM sent a TA to the UE.

[0269] Optionally, the handover notification message may also include target cell information and beam information, and may also include the TA of the candidate cell for continuous LTM.

[0270] Step S607: The CU sends a handover notification message to the target DU. Correspondingly, the target DU receives the handover notification message from the CU.

[0271] Optionally, the handover notification message sent by the CU to the target DU may be the same as or different from the handover notification message sent by the CU to the target DU; this application does not limit this. For example, the handover notification message sent by the CU to the target DU may not include the first indication information.

[0272] Step S608: The UE performs RA-less LTM handover. If the handover is successful, proceed to case 1; otherwise, proceed to case 2.

[0273] Case 1 includes steps S609 to S611.

[0274] Step S609: The UE accesses the target cell in a random access manner based on the second indication information indicated by the target DU.

[0275] The second indication information is used to indicate the TA value, such as TA value5.

[0276] For example, the UE performs cell selection, selects the target cell indicated in step 4 above, attempts to access the target cell in a random access manner, and successfully accesses the target cell based on the TA value indicated by the target DU response (i.e. the TA value indicated by the second indication information).

[0277] Step S610: The target DU sends the second indication information to the CU. Correspondingly, the CU receives the second indication information from the target DU.

[0278] Step S611: The CU performs mobility parameter optimization analysis based on the first indication information and the second indication information, or the CU sends the first indication information and the second indication information to the source DU.

[0279] Case 2 includes steps S612 to S615. Case 2 is: the UE successfully performs RA-less LTM handover, that is, it successfully sends the first uplink data packet based on the TA (such as TA value1 mentioned above) included in the LTM handover command.

[0280] Step S612: The target DU instructs the UE to adjust the TA value.

[0281] For example, the target DU instructs the UE to adjust the TA value to TA value 5.

[0282] For example, the target DU instructs the UE to adjust the TA value via MAC CE command, such as instructing the UE to adjust the TA value to TA value5.

[0283] For example, the target DU can determine the UE's TA value by measuring the UE's uplink transmission. If the UE needs correction, the target DU can send a timing advance command to the UE, requesting it to adjust the uplink transmission TA. For example, this timing advance command is sent to the UE via the Timing Advance Command MAC control element.

[0284] Step S613: The UE performs uplink transmission based on the adjusted TA value.

[0285] For example, if the target DU instructs the UE to adjust the TA value to TA value5, then the UE performs uplink transmission based on TA value5.

[0286] Step S614: The target DU sends third indication information to the CU, which indicates the adjusted TA value. Correspondingly, the CU receives the third indication information from the target DU.

[0287] For example, if the target DU instructs the UE to adjust the TA value to TAvalue5, then the UE performs uplink transmission based on TA value5.

[0288] In one possible implementation, the target DU detects that the UE quickly adjusted its TA value (to TA value 5) after the first uplink transmission to prepare for sending subsequent uplink data packets. "Quickly" can mean after the first uplink data transmission, after the first N uplink data packet transmissions made by the UE to the target DU, or within a preset time after the first uplink data transmission; this scheme does not impose any restrictions. Here, N is an integer greater than 1. The target DU sends TA information to the CU used by the UE. The TA information can include the TA value 5 used to send subsequent uplink data packets, or the TA value 5 to which the UE adjusted its TA. Optionally, the TA information can also include UE identification information.

[0289] Step S615: The CU performs mobility parameter optimization analysis based on the first indication information and the third indication information, or the CU sends the first indication information and the third indication information to the source DU.

[0290] The implementation of step S615 can be exemplarily referred to in the relevant content of step S503 above, and will not be repeated here.

[0291] Step S616: The CU sends the first information to the source DU. Correspondingly, the source DU receives the first information from the CU.

[0292] Step S613 is an optional step.

[0293] For example, the first information may include at least one of the following: invalid TA, TA value1, TA value5, or TA difference. Wherein, invalid TA may be determined by the target DU based on step S611; TA value1 may be the TA value carried by the LTM switching command (i.e., the TA value indicated by the second indication information); TA value5 may be TA value5 in case 1 (i.e., the TA value indicated by the second indication information) or TA value5 in case 2 (i.e., the TA value indicated by the third indication information); TA difference may be the difference between TA value1 and TA value5.

[0294] Figure 7 This is a flowchart illustrating another communication method provided in an embodiment of this application.

[0295] In this application embodiment, the steps performed by the third communication device can also be performed by the module of the third communication device (e.g., a chip, chip system, integrated circuit, or control unit); in this application embodiment, the steps performed by the fifth communication device can also be performed by the module of the fifth communication device (e.g., a chip, chip system, integrated circuit, or control unit).

[0296] like Figure 7 As shown, the communication method may include some or all of the following steps:

[0297] Step S701: The second communication device sends second information to the third communication device. The second information includes second indication information or third indication information. The second indication information is used to instruct the terminal device to use second timing advance information to access the first cell based on random access. Access to the first cell based on random access is triggered by the failure of access to the first cell without random access. The third indication information is used to instruct the terminal device to use third timing advance information to execute the second uplink transmission after successfully accessing the first cell without random access.

[0298] Accordingly, the third communication device receives the second information sent by the second communication device. In one possible implementation, the third communication device receives the second information sent from the fifth communication device via the second communication device.

[0299] For example, the third communication device is the DU (or source DU) corresponding to the source DU (or second cell) where the terminal device is located before accessing the first cell, and the fifth communication device is the DU (or target DU) corresponding to the first cell (or target cell). Then, the fifth communication device sends the second information to the third communication device, specifically by the target DU sending the second information to the source DU through the CU. For example, the target DU sends the second information to the CU, and the CU then sends the second information to the source DU. The specific implementation in this scenario can be found below. Figure 8 Examples will not be elaborated here.

[0300] For example, the second information includes one or more of the downlink RRC message transfer message or the access and mobility indication message.

[0301] Optionally, the second information also includes an identifier for identifying the terminal device. For example, when the second information is sent via a downlink RRC message transfer message, the identifier for identifying the terminal device is the interface identifier (F1AP ID) assigned to the terminal device by the third and second communication devices; when the second message is sent via an Access and Mobility Indication message, the identifier for identifying the terminal device is the Cell Radio Network Temporary Identifier (C-RNTI) assigned to the terminal device by the first or second cell.

[0302] Step S702: The third communication device performs mobility parameter optimization analysis based on the second information.

[0303] The second information can be either a second instruction or a third instruction.

[0304] Optionally, the third communication device receives the first indication information. For example, the first indication information is included in an Access and Mobility Indication message. For example, the Access and Mobility Indication message received by the third communication device may include one or more of the first indication information, second information, and a Radio Link Failure Report (RLF report) corresponding to the terminal device.

[0305] Optionally, the third communication device may perform mobility parameter optimization analysis based on the first indication information and the second indication information; or, perform mobility parameter optimization analysis based on the first indication information and the third indication information; wherein, the first indication information is used to indicate the first timing advance information, which is the timing advance information used by the terminal device to perform the first uplink transmission when accessing the first cell in a non-random access manner.

[0306] Wherein, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to instruct the terminal device to send a first timing advance, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0307] For example, the process of the third communication device performing mobility parameter optimization analysis is as follows: The second communication device identifies / determines whether there is an issue with the timing advance used during random access exemption being invalid or failing too quickly. Specifically, it determines whether the first timing advance is invalid based on whether the difference between the first timing advance and the second timing advance is too large, or it determines whether the first timing advance fails too quickly based on whether the timing advance adjustment by the terminal device (from the first uplink timing advance to the third timing advance) occurs within a very short time after the first uplink transmission (such as within a preset period of time). If the first timing advance is invalid or fails too quickly, the third communication device optimizes the timing advance acquisition and management process.

[0308] above Figure 7 The method embodiments shown include many possible implementation schemes, which will be discussed below. Figure 8 Some of the implementation schemes will be illustrated with examples. It should be noted that... Figure 8 For any unexplained related concepts, operations, or logical relationships, please refer to [link / reference]. Figure 7 The corresponding description in the illustrated embodiment.

[0309] In this application, Figure 8 The illustrated embodiment can be considered as a standalone embodiment. Figure 8 The embodiments shown can all be implemented without relying on Figure 7 The technical solution; Figure 8 Some of the steps in the illustrated embodiments can also be used as separate embodiments.

[0310] Figure 8 This is a schematic diagram of another communication method provided in an embodiment of this application. Figure 8 The method is exemplified by using the third communication device as the source DU, the fifth communication device as the target DU, the second communication device as the CU, and the terminal device as the UE. The method includes some or all of the following steps:

[0311] The specific content of steps S801 to S805 can be exemplarily referred to steps S401 to S405 above, and will not be repeated here.

[0312] Step S806: The source DU sends a handover notification message to the target DU. Correspondingly, the target DU receives the handover notification message from the source DU.

[0313] For example, the source DU sends a handover notification message to the target DU via the CU. The specific content of this handover notification message can be found in [example description]. Figure 2A The switching notification message in the middle is not described in detail here.

[0314] Step S807: The UE performs RA-less LTM handover. If the handover is successful, proceed to Case 1; otherwise, proceed to Case 2.

[0315] Case 1 may include steps S808 to S810.

[0316] Step S808: The UE accesses the target cell via random access based on the second indication information indicated by the target DU. The second indication information indicates the TA value, such as TAvalue5.

[0317] The second indication information is used to indicate the TA value, such as TA value5.

[0318] Step S809: The target DU sends the second indication information to the source DU. Correspondingly, the source DU receives the second indication information from the target DU.

[0319] For example, the target DU sends a second instruction message to the source DU via the CU.

[0320] Step S810: The source DU performs mobility parameter optimization analysis based on the first indication information and the second indication information.

[0321] The first indication information is used to instruct the source DU to send TA information in the LTM handover command to the UE. That is to say, the source DU performs mobility parameter optimization analysis based on the TA information and the second indication information in the LTM handover command it sends to the UE.

[0322] The TA information in the LTM handover command includes at least one of the following: whether the LTM handover command indicates a TA, and the TA value indicated in the LTM handover command (also known as the TA value of the LTM target cell sent to the UE).

[0323] For example, if the LTM handover command includes TA value1, and TA value1 is used by the UE to perform random access-free operation, then the first indication information may include TA value1, or the first indication information may be TA value1, or the first indication information may be used to indicate TA value1.

[0324] Case 2 may include steps S811 to S814. Case 2 is: the UE successfully performs RA-less LTM handover, that is, it successfully sends the first uplink data packet based on the TA (such as TA value1 mentioned above) included in the LTM handover command.

[0325] Step S811: The target DU instructs the UE to adjust the TA value.

[0326] For example, the target DU instructs the UE to adjust the TA value to TA value 5.

[0327] For example, the target DU instructs the UE to adjust the TA value via MAC CE command, such as instructing the UE to adjust the TA value to TA value5.

[0328] For example, the target DU can determine the UE's TA value by measuring the UE's uplink transmission. If a particular UE needs correction, a Timing Advance Command is sent to that UE, requesting it to adjust its uplink transmission TA. For example, this Timing Advance Command is sent to the UE via the Timing Advance Command MAC control element.

[0329] Step S812: The UE performs uplink transmission based on the adjusted TA value.

[0330] For example, if the target DU instructs the UE to adjust the TA value to TA value5, then the UE performs uplink transmission based on TA value5.

[0331] Step S813: The target DU sends third indication information to the source DU through the CU. The third indication information is used to indicate the adjusted TA value. Correspondingly, the source DU receives the third indication information from the target DU through the CU.

[0332] For example, if the target DU instructs the UE to adjust the TA value to TA value5, then the third indication information is used to indicate TA value5. For instance, the third indication information can be TA value5.

[0333] In one possible implementation, the target DU identifies that the UE quickly adjusted its TA value (to TA value 5) after the first uplink transmission for use in sending TA information used by the UE to the source DU via the CU. The TA information may include TA value 5 used for sending subsequent uplink data packets, or TA value 5 to which the UE adjusted its TA. Optionally, the TA information may also include UE identification information.

[0334] Step S814: The source DU performs mobility parameter optimization analysis based on the third indication information.

[0335] For example, the source DU performs mobility parameter optimization analysis based on the first indication information and the third indication information.

[0336] In one implementation, the source DU obtains the first indication information (i.e., the TA information in the LTM handover command sent by the source DU to the UE) and the received third indication information based on the UE context stored in the source DU, and performs mobility parameter optimization analysis. In another implementation, the source DU performs mobility parameter optimization analysis based on the first indication information obtained from the CU and the received third indication information.

[0337] The foregoing details the method provided in this application. To facilitate the implementation of the above-described solutions in the embodiments of this application, corresponding apparatus or devices are also provided in the embodiments of this application.

[0338] This application divides the first to fifth communication devices into functional modules according to the above-described method embodiments. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application is illustrative and represents only one logical functional division; in actual implementation, other division methods may be used. The following will combine... Figures 9 to 11 The communication device of the embodiments of this application is described in detail.

[0339] See Figure 9 , Figure 9 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Figure 9 As shown, the communication device may include a transceiver unit 901 and a processing unit 902.

[0340] In some embodiments of this application, the communication device may be the first communication device shown above or a chip or circuit disposed in the first communication device. That is, the communication device may be used to perform the steps or functions performed by the first communication device in the method embodiments described above.

[0341] In one design, the transceiver unit 901 is configured to: receive first indication information, the first indication information being used to indicate first timing advance information, the first timing advance information being timing advance information used by the terminal device to perform the first uplink transmission when accessing the first cell in a non-random access manner; and the processing unit 902 is configured to: perform mobility parameter optimization analysis based on the first indication information.

[0342] In one possible implementation, the processing unit 902 is specifically used to: perform mobility parameter optimization analysis based on the first indication information and the second indication information; or, perform mobility parameter optimization analysis based on the first indication information and the third indication information; wherein, the second indication information is used to instruct the terminal device to use the second timing advance information for accessing the first cell based on random access, the access to the first cell based on random access is triggered by the failure of access to the first cell without random access; the third indication information is used to instruct the terminal device to execute the third timing advance information for the second uplink transmission after successfully accessing the first cell, or to instruct the terminal device to execute the third timing advance information for the second uplink transmission after a timing advance adjustment occurs.

[0343] Optionally, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to instruct the terminal device to send a first timing advance, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0344] For example, the first indication information is included in the handover notification message, wherein the first indication information is used to indicate whether the LTM handover command sent by the second cell to the terminal device includes a timing advance, and / or the first timing advance included in the LTM handover command, and the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0345] Optionally, the first indication information is included in one or more of the following: a handover notification message (DU-CU CELL SWITCH NOTIFICATION message, and / or a CU-DU CELL SWITCH NOTIFICATION message), or an RRC message transfer message (ULRRC MESSAGE TRANSFER message, and / or a DL RRC MESSAGE TRANSFER message).

[0346] Optionally, the second information may also include an identifier for identifying the terminal device.

[0347] In one possible implementation, the transceiver unit 901 is further configured to: send first information, wherein the first information includes at least one of the following: the failure to access the first cell without random access is caused by an invalid timing advance, a first timing advance, a second timing advance, or a first difference, wherein the first difference is the difference between the first timing advance and the second timing advance, the first timing advance is the timing advance used by the terminal device to perform the first uplink transmission when accessing the first cell without random access, and the second timing advance is the timing advance used by the terminal device to access the first cell based on random access.

[0348] Specific details in the embodiments of this application can be exemplarily referred to above. Figure 3 and Figure 4 The descriptions in the method embodiments shown will not be repeated here.

[0349] It is understood that the specific descriptions of the transceiver unit 901 and the processing unit 902 shown in the embodiments of this application are merely examples. For the specific functions or execution steps of the transceiver unit 901 and the processing unit 902, please refer to the above descriptions. Figure 3 and Figure 4 The method embodiments shown are not described in detail here. Furthermore, the technical effects of the embodiments of this application are explained in the foregoing. Figure 3 and Figure 4 The technical effects of the method embodiments shown are not elaborated here for the sake of simplicity.

[0350] Reuse Figure 9 In some embodiments of this application, the communication device may be the second communication device shown above, or a chip or circuit disposed in the second communication device. That is, the communication device may be used to perform the steps or functions performed by the second communication device in the method embodiments described above.

[0351] In one design, a transceiver unit 901 is configured to receive first indication information, which indicates first timing advance information, the first timing advance information being the timing advance information used by the terminal device to perform a first uplink transmission when accessing the first cell using a non-random access method; and to receive second information, which includes a second indication information or a third indication information, wherein the second indication information indicates the second timing advance information used by the terminal device to access the first cell using a random access method, the random access method being triggered by a failure to access the first cell using a non-random access method; the third indication information indicates the third timing advance information used by the terminal device to perform a second uplink transmission after successfully accessing the first cell using a non-random access method, or indicates the terminal device to perform a third timing advance information used by the terminal device to perform a second uplink transmission after a timing advance adjustment occurs; and a processing unit 902 is configured to: perform mobility parameter optimization analysis based on the first indication information and the second information, or the transceiver unit 901 is configured to send the first indication information and / or the second indication information.

[0352] Optionally, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to instruct the terminal device to send a first timing advance, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0353] For example, the first indication information is included in the handover notification message, wherein the first indication information is used to indicate whether the LTM handover command sent by the second cell to the terminal device includes a timing advance, and / or the first timing advance included in the LTM handover command, and the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0354] For example, the transceiver unit 901 is specifically configured to: receive the first indication information through one or more of the following: a DU-CU CELL SWITCH NOTIFICATION message, an uplink RRC message transfer message, or an Access and Mobility Indication message; and send the first indication information through one or more of the following: a DU-CU CELL SWITCH NOTIFICATION message, an downlink RRC message transfer message, or an Access and Mobility Indication message.

[0355] Optionally, the second information may also include an identifier for identifying the terminal device.

[0356] In one possible implementation, the transceiver unit 901 is further configured to: send first information, wherein the first information includes at least one of the following: the failure to access the first cell without random access is caused by an invalid timing advance, a first timing advance, a second timing advance, or a first difference, wherein the first difference is the difference between the first timing advance and the second timing advance, the first timing advance is the timing advance used by the terminal device to perform the first uplink transmission when accessing the first cell without random access, and the second timing advance is the timing advance used by the terminal device to access the first cell based on random access.

[0357] Specific details in the embodiments of this application can be exemplarily referred to above. Figure 5 and Figure 6 The descriptions in the method embodiments shown will not be repeated here.

[0358] It is understood that the specific descriptions of the transceiver unit 901 and the processing unit 902 shown in the embodiments of this application are merely examples. For the specific functions or execution steps of the transceiver unit 901 and the processing unit 902, please refer to the above descriptions. Figure 3 and Figure 4 The method embodiments shown are not described in detail here. Furthermore, the technical effects of the embodiments of this application are explained in the foregoing. Figure 3 and Figure 4 The technical effects of the method embodiments shown are not elaborated here for the sake of simplicity.

[0359] Reuse Figure 9 In some embodiments of this application, the communication device may be the third communication device shown above, or a chip or circuit disposed in the third communication device. That is, the communication device may be used to perform the steps or functions performed by the third communication device in the method embodiments above.

[0360] In one design, the transceiver unit 901 is configured to: receive second information, the second information including second indication information or third indication information, wherein the second indication information is configured to instruct the terminal device to use second timing advance information for accessing the first cell based on random access, the access to the first cell based on random access is triggered by the failure of access to the first cell without random access, the third indication information is configured to instruct the terminal device to execute third timing advance information for second uplink transmission after successfully accessing the first cell without random access, or to instruct the terminal device to execute third timing advance information for second uplink transmission after a timing advance adjustment occurs; the processing unit 902 is configured to: perform mobility parameter optimization analysis based on the second information.

[0361] In one design, the transceiver unit 901 is also used to: send first instruction information.

[0362] In one possible implementation, the transceiver unit 901 is further configured to: receive second information, which includes second indication information or third indication information. For example, the second information may be included in one or more of a downlink RRC message transfer message or an access and mobility indication message. For example, the second information may also include an identifier for identifying the terminal device.

[0363] In one possible implementation, the transceiver unit 901 is further configured to: receive first instruction information.

[0364] For example, the first indication information is included in the Access and Mobility Indication message.

[0365] In one possible implementation, the processing unit 902 is specifically used to: perform mobility parameter optimization analysis based on the first indication information and the second indication information; or, perform mobility parameter optimization analysis based on the first indication information and the third indication information; wherein the first indication information is used to indicate the first timing advance information, which is the timing advance information used by the terminal device to perform the first uplink transmission when accessing the first cell in a non-random access manner.

[0366] In one possible implementation, the transceiver unit 901 is further configured to: receive first indication information. For example, the third communication device receives the first indication information via an access and mobility indication message, or simultaneously receives the first indication information and the second information via an access and mobility indication message.

[0367] Optionally, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to instruct the terminal device to send a first timing advance, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0368] Optionally, the second information may also include an identifier for identifying the terminal device.

[0369] Specific details in the embodiments of this application can be exemplarily referred to above. Figure 7 and Figure 8 The descriptions in the method embodiments shown will not be repeated here.

[0370] It is understood that the specific descriptions of the transceiver unit 901 and the processing unit 902 shown in the embodiments of this application are merely examples. For the specific functions or execution steps of the transceiver unit 901 and the processing unit 902, please refer to the above descriptions. Figure 7 and Figure 8 The method embodiments shown are not described in detail here. Furthermore, the technical effects of the embodiments of this application are explained in the foregoing. Figure 7 and Figure 8 The technical effects of the method embodiments shown are not elaborated here for the sake of simplicity.

[0371] Reuse Figure 9 In some embodiments of this application, the communication device may be the fourth communication device shown above, or a chip or circuit disposed in the fourth communication device. That is, the communication device may be used to perform the steps or functions performed by the fourth communication device in the above method embodiments.

[0372] In one design, the transceiver unit 901 is used to: send first indication information, the first indication information being used to indicate first timing advance information, the first timing advance information being the timing advance information used by the terminal device to perform the first uplink transmission when accessing the first cell in a non-random access manner, and the first indication information being used for mobility parameter optimization analysis.

[0373] Optionally, the first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to instruct the terminal device to send a first timing advance, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0374] For example, the first indication information is included in the handover notification message, wherein the first indication information is used to indicate whether the LTM handover command sent by the second cell to the terminal device includes a timing advance, and / or the first timing advance included in the LTM handover command, and the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

[0375] In one possible implementation, the transceiver unit 901 is further configured to: receive first information, the first information being determined based on first instruction information.

[0376] Optionally, the first information includes at least one of the following: the failure to access the first cell without random access is caused by an invalid time advance, a first time advance, a second time advance, or a first difference, wherein the first difference is the difference between the first time advance and the second time advance, the first time advance is the time advance used by the terminal device to perform the first uplink transmission when accessing the first cell without random access, and the second time advance is the time advance used by the terminal device to access the first cell based on random access.

[0377] Specific details in the embodiments of this application can be exemplarily referred to above. Figures 3 to 6 The descriptions in the method embodiments shown will not be repeated here.

[0378] It is understood that the specific descriptions of the transceiver unit 901 and the processing unit 902 shown in the embodiments of this application are merely examples. For the specific functions or execution steps of the transceiver unit 901 and the processing unit 902, please refer to the above descriptions. Figures 3 to 6 The method embodiments shown are not described in detail here. Furthermore, the technical effects of the embodiments of this application are explained in the foregoing. Figures 3 to 6 The technical effects of the method embodiments shown are not elaborated here for the sake of simplicity.

[0379] Reuse Figure 9 In some embodiments of this application, the communication device may be the fifth communication device shown above, or a chip or circuit disposed in the fifth communication device. That is, the communication device may be used to perform the steps or functions performed by the fifth communication device in the method embodiments described above.

[0380] In one design, the transceiver unit 901 is used to: transmit second information, the second information including second indication information or third indication information, the second information being used for mobility parameter optimization analysis, wherein the second indication information is used to instruct the terminal device to use second timing advance information for accessing the first cell based on random access, the access to the first cell based on random access being triggered by the failure of access to the first cell without random access, the third indication information is used to instruct the terminal device to execute third timing advance information for second uplink transmission after successfully accessing the first cell without random access, or to instruct the terminal device to execute third timing advance information for second uplink transmission after a timing advance adjustment occurs.

[0381] Optionally, the second information may also include an identifier for identifying the terminal device.

[0382] Specific details in the embodiments of this application can be exemplarily referred to above. Figures 5 to 8 The descriptions in the method embodiments shown will not be repeated here.

[0383] It is understood that the specific descriptions of the transceiver unit 901 and the processing unit 902 shown in the embodiments of this application are merely examples. For the specific functions or execution steps of the transceiver unit 901 and the processing unit 902, please refer to the above descriptions. Figures 5 to 8 The method embodiments shown are not described in detail here. Furthermore, the technical effects of the embodiments of this application are explained in the foregoing. Figures 5 to 8 The technical effects of the method embodiments shown are not elaborated here for the sake of simplicity.

[0384] The following describes the possible product forms of the first to fifth communication devices. It should be understood that any device possessing the above-mentioned features... Figure 9 Any form of product that incorporates the functions of the first to fifth communication devices falls within the protection scope of this application. It should also be understood that the following description is merely illustrative and does not limit the product form of the communication devices in this application to these specific examples.

[0385] In one possible implementation, Figure 9 In the communication device shown, processing unit 902 can be a processing circuit, and transceiver unit 901 can be a communication circuit. The processing circuit can be one or more processors, or all or part of the control or processing circuitry within one or more processors; the communication circuit can be a transceiver circuit, which can be a transceiver; when the communication device is a chip or chip system, the communication circuit can be an interface circuit; when the communication device is a server, the communication circuit can be an interface circuit or a transceiver circuit. Transceiver unit 901 can also be a transmitting unit and / or a receiving unit; the transmitting unit can be a transmitting circuit, and the receiving unit can be a receiving circuit, with the transmitting unit and receiving unit integrated into a single device.

[0386] In this embodiment, the processing circuit and the communication circuit can be coupled, etc., and the connection method between the processing circuit and the communication circuit is not limited in this embodiment. During the execution of the above method, the process of sending information can be understood as the process of the processing circuit outputting the information. When outputting the information, the processing circuit outputs the information to the communication circuit for transmission. After being output by the processing circuit, the information may require further processing before reaching the communication circuit. Similarly, the process of receiving information in the above method can be understood as the process of the processing circuit receiving the input information. When the processing circuit receives the input information, the communication circuit receives the information and inputs it into the processing circuit. Furthermore, after the communication circuit receives the information, the information may require further processing before being input into the processing circuit.

[0387] In one possible implementation, Figure 9In the communication device shown, the processing unit 902 can be one or more processors, and the transceiver unit 901 can be a transceiver, or the transceiver unit 901 can also be a transmitting unit and / or a receiving unit. The transmitting unit can be a transmitter, and the receiving unit can be a receiver. The transmitting unit and the receiving unit are integrated into one device, such as a transceiver. In the embodiments of this application, the processor and the transceiver can be coupled, etc., and the connection method between the processor and the transceiver is not limited in the embodiments of this application. In the process of executing the above method, the process of sending information in the above method can be understood as the process of the processor outputting the above information. When outputting the above information, the processor outputs the above information to the transceiver so that the transceiver can transmit it. After the above information is output by the processor, it may need to undergo other processing before reaching the transceiver. Similarly, the process of receiving information in the above method can be understood as the process of the processor receiving the input above information. When the processor receives the input information, the transceiver receives the above information and inputs it into the processor. Furthermore, after the transceiver receives the above information, the above information may need to undergo other processing before being input into the processor.

[0388] See Figure 10 , Figure 10 This is another structural schematic diagram of the communication device provided in the embodiments of this application. For example... Figure 10 As shown, the communication device provided in this application embodiment can be used to implement the methods described in the above method embodiments, and the description in the above method embodiments can be referred to. The communication device can be any one of the first to fifth communication devices, or a chip. For example, the communication device includes one or more processors 1001. The communication device may further include a memory 1003. Optionally, the communication device may further include a transceiver 1002. In one implementation, the communication device further includes an input / output device (...). Figure 10 (Not indicated).

[0389] The processor 1001 is mainly used to process communication protocols and communication data, control the entire communication device, execute software programs, and process the data of the software programs. The memory 1003 is mainly used to store software programs and data. The transceiver 1002 may include control circuitry and an antenna. The control circuitry is mainly used for converting baseband signals to radio frequency signals and processing radio frequency signals. The antenna is mainly used for transmitting and receiving radio frequency signals in the form of electromagnetic waves. Input / output devices, such as touchscreens, displays, and keyboards, are mainly used to receive user input data and output data to the user.

[0390] When the communication device is powered on, the processor 1001 can read the software program in the memory 1003, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processor 1001 performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency (RF) circuit. The RF circuit processes the baseband signal and transmits the RF signal outward in the form of electromagnetic waves through the antenna. When data is sent to the communication device, the RF circuit receives the RF signal through the antenna, converts the RF signal into a baseband signal, and outputs the baseband signal to the processor 1001. The processor 1001 converts the baseband signal into data and processes the data.

[0391] In another implementation, the radio frequency circuitry and antenna can be set up independently of the processor performing baseband processing. For example, in a distributed scenario, the radio frequency circuitry and antenna can be arranged remotely, independent of the communication device.

[0392] The processor 1001, transceiver 1002, and memory 1003 can be connected via a communication bus.

[0393] For example, when the communication device is used to perform the above... Figure 3 When the first communication device performs a step, method, or function in the illustrated embodiment, the transceiver 1002 can be used to perform... Figure 3 In step S301, the processor 1001 can be used to execute step S302. When the communication device is used to execute the above... Figure 3 When the fourth communication device in the illustrated embodiment performs a step, method, or function, the transceiver 1002 can be used to perform... Figure 3 Step S301 in the process.

[0394] For example, when the communication device is used to perform the above... Figure 5 In the illustrated embodiment, when the second communication device performs a step, method, or function, the transceiver 1002 can be used to perform... Figure 5 In steps S501 and S502, the processor 1001 can be used to execute step S503. When the communication device is used to execute the above... Figure 5 When the fourth communication device in the illustrated embodiment performs a step, method, or function, the transceiver 1002 can be used to perform... Figure 5 S501 in the above. When the communication device is used to perform the above... Figure 5 When the fifth communication device in the illustrated embodiment performs a step, method, or function, the transceiver 1002 can be used to perform... Figure 5 Step S502 in the process.

[0395] For example, when the communication device is used to perform the above... Figure 7When the third communication device performs a step, method, or function in the illustrated embodiment, the transceiver 1002 can be used to perform... Figure 7 In step S701, processor 1001 can be used to execute step S702. When the communication device is used to execute the above... Figure 7 When the fifth communication device in the illustrated embodiment performs a step, method, or function, the transceiver 1002 can be used to perform... Figure 7 S701 in the middle.

[0396] In any of the above implementations, the processor 1001 may include a transceiver for implementing receiving and transmitting functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, or interface circuit can be used for reading and writing code / data, or it can be used for transmitting or relaying signals.

[0397] In any of the above implementations, the processor 1001 may store instructions, which may be computer programs. These computer programs, running on the processor 1001, cause the communication device to execute the methods described in the above method embodiments. The computer program may be embedded in the processor 1001; in this case, the processor 1001 may be implemented in hardware.

[0398] In one implementation, the communication device may include a circuit that can perform the functions of transmitting, receiving, or communicating in the aforementioned method embodiments. The processor and transceiver described in this application can be implemented on integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed-signal ICs, application-specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal-oxide semiconductors (CMOS), n-metal-oxide-semiconductor (NMOS), positive-channel metal-oxide semiconductors (PMOS), bipolar junction transistors (BJTs), bipolar CMOS (BiCMOS), silicon-germanium (SiGe), gallium arsenide (GaAs), etc.

[0399] It is understood that the communication device shown in the embodiments of this application may also have more than Figure 10 This application does not limit the use of other components or other related elements. The methods performed by the processor and transceiver shown above are merely examples; for the specific steps performed by the processor and transceiver, please refer to the description of the method embodiments above.

[0400] In another possible implementation, the communication device provided in this application embodiment may include one or more processors and a memory. The processor executes a program stored in the memory, and when the program is executed, the method embodiment described above is performed. Exemplarily, the processor and memory may also be integrated into a single device, i.e., the processor and memory may be integrated together. For more details regarding the processor and memory, please refer to... Figure 10 The relevant information regarding the processor 1001 and memory 1003.

[0401] In another possible implementation Figure 10The communication device shown may also include a processing unit, which may be one or more logic circuits. The transceiver unit 901 may be an input / output interface, or a communication interface, or an interface circuit, or an interface, etc. Alternatively, the transceiver unit 901 may also be a transmitting unit and a receiving unit. The transmitting unit may be an output interface, and the receiving unit may be an input interface. The transmitting unit and the receiving unit are integrated into one unit, such as an input / output interface.

[0402] See Figure 11 , Figure 11 This is yet another structural schematic diagram of the communication device provided in the embodiments of this application. For example... Figure 11 As shown, Figure 11 The communication device shown includes logic circuit 1101 and interface 1102. That is, the processing unit can be implemented using logic circuit 1101, and the transceiver unit 901 can be implemented using interface 1102. The logic circuit 1101 can be a chip, processing circuit, integrated circuit, or system-on-chip (SoC) chip, etc., and the interface 1102 can be a communication interface, input / output interface, pins, etc. For example, Figure 11 The above-mentioned communication device is used as an example of a chip, which includes a logic circuit 1101 and an interface 1102.

[0403] In this embodiment, the logic circuit and the interface can also be coupled to each other. The specific connection method between the logic circuit and the interface is not limited in this embodiment.

[0404] For example, when the communication device is used to perform the above... Figure 3 When the first or fourth communication device performs a step, method, or function in the method embodiment shown, interface 1102 is used to transmit first instruction information.

[0405] For example, when the communication device is used to perform the above... Figure 5 When the fourth or second communication device in the illustrated method embodiment performs a step, method, or function, interface 1102 is used to transmit first indication information. When the communication device is used to perform the above... Figure 5 When the fifth or second communication device performs a step, method, or function in the method embodiment shown, interface 1102 is used to transmit second information.

[0406] For example, when the communication device is used to perform the above... Figure 7 When the third or fifth communication device in the method embodiment shown performs a step, method, or function, interface 1102 is used to transmit second information.

[0407] In the embodiments of this application, the descriptions of the first information, the second information, and the first reference signal, etc., can be found above. Figure 3 The method embodiments shown are described in detail here, and will not be repeated here. It is understood that for a more detailed explanation of the logic circuit 1101 and interface 1102, please refer to [the relevant documentation / reference needed]. Figure 9 The descriptions of the processing unit and transceiver unit shown will not be repeated here.

[0408] It is understood that the communication device shown in the embodiments of this application can implement the method provided in the embodiments of this application in hardware form or in software form, etc., and the embodiments of this application do not limit it in this way.

[0409] for Figure 11 For specific implementations of the various embodiments shown, please refer to the above embodiments, which will not be described in detail here.

[0410] This application also provides a communication system, which includes a first communication device and a fourth communication device, the first communication device and the fourth communication device being able to perform the aforementioned... Figures 3 to 4 The method in any of the method embodiments.

[0411] This application also provides a communication system, which includes a second communication device, a fourth communication device, and a fifth communication device. The second communication device, the fourth communication device, and the fifth communication device can be used to perform the aforementioned tasks. Figures 5 to 6 The method in any of the method embodiments.

[0412] This application also provides a communication system, which includes a third communication device and a fifth communication device, which can be used to perform the aforementioned tasks. Figures 7 to 8 The method in any of the method embodiments.

[0413] In addition, this application also provides a computer program for implementing the operations and / or processes performed by a communication device (such as the first to fifth communication devices described above) in the method provided in this application.

[0414] This application also provides a computer-readable storage medium storing computer code that, when executed on a computer, causes the computer to perform the operations and / or processes performed by a communication device (such as the first to fifth communication devices described above) in the method provided in this application.

[0415] This application also provides a computer program product, which includes computer code or a computer program that, when run on a computer, causes the operations and / or processes performed by a communication device (such as the first to fifth communication devices described above) in the method provided in this application to be executed.

[0416] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, or it may be an electrical, mechanical, or other form of connection.

[0417] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected according to actual needs to achieve the technical effects of the solutions provided in the embodiments of this application.

[0418] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0419] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or communication device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned readable storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0420] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, The method is applied to a first communication device, and the method includes: Receive first indication information, the first indication information is used to indicate first time advance information, the first time advance information is the time advance information used by the terminal device to perform the first uplink transmission when it accesses the first cell in a non-random access manner; Based on the first indication information, perform mobility parameter optimization analysis.

2. The method as described in claim 1, characterized in that, The step of performing mobility parameter optimization analysis based on the first indication information includes: Based on the first and second indication information, perform mobility parameter optimization analysis; Alternatively, based on the first and third indication information, perform mobility parameter optimization analysis; The second indication information is used to indicate the second timing advance information used by the terminal device to access the first cell based on random access, wherein the access to the first cell based on random access is triggered by the failure of access to the first cell without random access; the third indication information is used to indicate the third timing advance information used by the terminal device to execute the second uplink transmission after successfully accessing the first cell.

3. The method as described in claim 1 or 2, characterized in that, The first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to indicate a first timing advance to the terminal device, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

4. The method according to any one of claims 1-3, characterized in that, The first indication information is included in the handover notification message, wherein the first indication information is used to indicate whether the layer 1 / layer 2 triggered mobility handover command sent by the second cell to the terminal device includes a timing advance, and / or the layer 1 / layer 2 triggered mobility handover command includes a first timing advance, and the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

5. The method according to any one of claims 2-4, characterized in that, The method further includes: Send first information, wherein the first information includes at least one of the following: the failure to access the first cell using the non-random access method is caused by an invalid time advance, a first time advance, a second time advance, or a first difference, wherein the first difference is the difference between the first time advance and the second time advance, the first time advance is the time advance used by the terminal device to perform the first uplink transmission when accessing the first cell using the non-random access method, and the second time advance is the time advance used by the terminal device to access the first cell using the random access method.

6. A communication method, characterized in that, The method is applied to a second communication device, and the method includes: Receive first indication information, the first indication information is used to indicate first time advance information, the first time advance information is the time advance information used by the terminal device to perform the first uplink transmission when it accesses the first cell in a non-random access manner; Receive second information, the second information including second indication information or third indication information, wherein the second indication information is used to instruct the terminal device to use second timing advance information to access the first cell based on random access, the access to the first cell based on random access is triggered by the failure of access to the first cell without random access, and the third indication information is used to instruct the terminal device to execute third timing advance information for second uplink transmission after successfully accessing the first cell without random access. Based on the first indication information and the second information, perform mobility parameter optimization analysis; or, send the first indication information and / or the second indication information.

7. The method as described in claim 6, characterized in that, The first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to indicate a first timing advance to the terminal device, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

8. The method as described in claim 6 or 7, characterized in that, The first indication information is included in the handover notification message, wherein the first indication information is used to indicate whether the layer 1 / layer 2 triggered mobility handover command sent by the second cell to the terminal device includes a timing advance, and / or the layer 1 / layer 2 triggered mobility handover command includes a first timing advance, and the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

9. The method according to any one of claims 6-8, characterized in that, The second information also includes an identifier for identifying the terminal device.

10. The method according to any one of claims 7-9, characterized in that, The method further includes: Send first information, wherein the first information includes at least one of the following: the failure to access the first cell using the non-random access method is caused by an invalid time advance, a first time advance, a second time advance, or a first difference, wherein the first difference is the difference between the first time advance and the second time advance, the first time advance is the time advance used by the terminal device to perform the first uplink transmission when accessing the first cell using the non-random access method, and the second time advance is the time advance used by the terminal device to access the first cell using the random access method.

11. A communication method, characterized in that, The method is applied to a third communication device, and the method includes: Receive second information, the second information including second indication information or third indication information, wherein the second indication information is used to instruct the terminal device to use second timing advance information to access the first cell based on random access, the access to the first cell based on random access is triggered by the failure of access to the first cell without random access, and the third indication information is used to instruct the terminal device to use third timing advance information to execute the second uplink transmission after successfully accessing the first cell without random access. Based on the second information, a mobility parameter optimization analysis is performed.

12. The method as described in claim 11, characterized in that, The method further includes: Receive first indication information, wherein the first indication information is used to indicate first time advance information, and the first time advance information is the time advance information used by the terminal device to perform the first uplink transmission when accessing the first cell in a non-random access manner.

13. The method as described in claims 11 and 12, characterized in that, The step of performing mobility parameter optimization analysis based on the second information includes: Based on the first indication information and the second indication information, perform mobility parameter optimization analysis; Alternatively, based on the first indication information and the third indication information, perform mobility parameter optimization analysis; Wherein, the first indication information is used to indicate the first time advance information, which is the time advance information used by the terminal device to perform the first uplink transmission when it accesses the first cell in a non-random access manner.

14. The method according to any one of claims 11-13, characterized in that, The first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to indicate a first timing advance to the terminal device, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

15. The method according to any one of claims 11-14, characterized in that, The second information also includes an identifier for identifying the terminal device.

16. A communication method, characterized in that, The method is applied to a fourth communication device, and the method includes: Send a first indication message, the first indication message being used to indicate a first time advance information, the first time advance information being the time advance information used by the terminal device to perform the first uplink transmission when accessing the first cell in a non-random access manner, the first indication message being used for mobility parameter optimization analysis.

17. The method as described in claim 16, characterized in that, The first indication information is used to instruct the second cell to send a timing advance to the terminal device or not to send a timing advance to the terminal device, and / or, the first indication information is used to instruct the second cell to indicate a first timing advance to the terminal device, wherein the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

18. The method as described in claim 16 or 17, characterized in that, The first indication information is included in the handover notification message, wherein the first indication information is used to indicate whether the layer 1 / layer 2 triggered mobility handover command sent by the second cell to the terminal device includes a timing advance, and / or the layer 1 / layer 2 triggered mobility handover command includes the first timing advance, and the second cell is the source cell that instructs the terminal device to access the first cell in a manner that avoids random access.

19. The method according to any one of claims 16-18, characterized in that, The method further includes: Receive first information, which is determined based on the first indication information.

20. The method as described in claim 19, characterized in that, The first information includes at least one of the following: the failure to access the first cell using the non-random access method is caused by an invalid time advance, a first time advance, a second time advance, or a first difference, wherein the first difference is the difference between the first time advance and the second time advance, the first time advance is the time advance used by the terminal device to perform the first uplink transmission when accessing the first cell using the non-random access method, and the second time advance is the time advance used by the terminal device to access the first cell using the random access method.

21. A communication method, characterized in that, The method is applied to a fifth communication device, and the method includes: Send a second message, which includes a second indication message or a third indication message. The second message is used for mobility parameter optimization analysis. The second indication message is used to instruct the terminal device to use a second timing advance message for accessing the first cell based on random access. The access to the first cell based on random access is triggered by the failure of accessing the first cell without random access. The third indication message is used to instruct the terminal device to use a third timing advance message for second uplink transmission after successfully accessing the first cell without random access.

22. The method as described in claim 21, characterized in that, The second information also includes an identifier for identifying the terminal device.

23. A communication device, characterized in that, Includes units or modules for performing the method as described in any one of claims 1 to 22.

24. A communication device, characterized in that, The communication device includes at least one processor; the at least one processor is configured to perform the method as described in any one of claims 1 to 22.

25. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a program that, when run on the device, causes the device to perform the method as described in any one of claims 1 to 22.

26. A computer program product, characterized in that, The computer program product includes a program or instructions that, when executed by a device, cause the device to perform the method as described in any one of claims 1 to 22.

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